diff --git a/.github/workflows/eval.yml b/.github/workflows/eval.yml
index 3f7db77b..e5dc496d 100644
--- a/.github/workflows/eval.yml
+++ b/.github/workflows/eval.yml
@@ -1,9 +1,12 @@
 # Real-corpus acceptance (Track R).
 #
-#   * owasp  (Phase 27 / Track R.0): Gate 6 vs a real OWASP BenchmarkJava
+#   * owasp    (Phase 27 / Track R.0): Gate 6 vs a real OWASP BenchmarkJava
 #     checkout (Java).
-#   * jsts   (Phase 28 / Track R.1): Gate 7 vs OWASP NodeGoat (Express, .js)
+#   * jsts     (Phase 28 / Track R.1): Gate 7 vs OWASP NodeGoat (Express, .js)
 #     and OWASP Juice Shop (TypeScript, .ts), one matrix row per corpus.
+#   * polyglot (Phase 29 / Track R.2): Gate 8 vs OWASP RailsGoat (Rails, .rb),
+#     DVWA (PHP), DVPWA (aiohttp, .py), gosec (Go) and the RustSec advisory-db
+#     (Rust negative control), one matrix row per corpus.
 #
 # Runs on every PR that touches the dynamic verifier (src/dynamic/), the
 # eval-corpus harness (tests/eval_corpus/), or the gate script itself.
@@ -201,3 +204,141 @@ jobs:
         run: |
           export ${{ matrix.corpus.env }}="${{ github.workspace }}/.eval-corpus/${{ matrix.corpus.name }}"
           scripts/m7_ship_gate.sh --sets ${{ matrix.corpus.name }}
+
+  polyglot:
+    name: eval / ${{ matrix.corpus.name }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        corpus:
+          - name: railsgoat
+            repo: https://github.com/OWASP/railsgoat
+            ref: rails.5.0.0
+            lang: ruby
+            env: NYX_RAILSGOAT_CORPUS
+            manifest: railsgoat.manifest.toml
+            ground_truth: railsgoat.json
+          - name: dvwa
+            repo: https://github.com/digininja/DVWA
+            ref: "2.5"
+            lang: php
+            env: NYX_DVWA_CORPUS
+            manifest: dvwa.manifest.toml
+            ground_truth: dvwa.json
+          - name: dvpwa
+            repo: https://github.com/anxolerd/dvpwa
+            # DVPWA ships no release tags; pin the default branch and let the
+            # cache key hold it stable.
+            ref: master
+            lang: python
+            env: NYX_DVPWA_CORPUS
+            manifest: dvpwa.manifest.toml
+            ground_truth: dvpwa.json
+          - name: gosec
+            repo: https://github.com/securego/gosec
+            ref: v2.26.1
+            lang: go
+            env: NYX_GOSEC_CORPUS
+            manifest: gosec.manifest.toml
+            ground_truth: gosec.json
+          - name: rustsec
+            repo: https://github.com/rustsec/advisory-db
+            # advisory-db ships no release tags; pin the default branch.  This
+            # is the Rust NEGATIVE CONTROL (advisory metadata, no scannable
+            # source) — its committed ground truth is empty by construction.
+            ref: main
+            lang: rust
+            env: NYX_RUSTSEC_CORPUS
+            manifest: rustsec.manifest.toml
+            ground_truth: rustsec.json
+    env:
+      # CI wall-clock budget: 15 min.  Override locally to tighten.
+      NYX_POLYGLOT_WALLCLOCK_BUDGET_SECONDS: "900"
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: stable
+          cache: true
+
+      - uses: taiki-e/install-action@nextest
+
+      # The dynamic verifier's per-language build pool (Phase 22/23) compiles
+      # its harnesses with a real toolchain.  Each matrix row sets up only the
+      # toolchain for its corpus's target language; the Rust row needs no extra
+      # step (the rust toolchain above covers it, and advisory-db has no
+      # buildable source anyway).
+      - name: Set up Ruby
+        if: matrix.corpus.lang == 'ruby'
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.3"
+
+      - name: Set up PHP
+        if: matrix.corpus.lang == 'php'
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.3"
+
+      - name: Set up Python
+        if: matrix.corpus.lang == 'python'
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Set up Go
+        if: matrix.corpus.lang == 'go'
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.22"
+
+      - name: Cache ${{ matrix.corpus.name }}
+        id: cache-corpus
+        uses: actions/cache@v4
+        with:
+          path: .eval-corpus/${{ matrix.corpus.name }}
+          key: polyglot-${{ matrix.corpus.name }}-${{ matrix.corpus.ref }}
+
+      - name: Clone ${{ matrix.corpus.name }} (${{ matrix.corpus.ref }})
+        if: steps.cache-corpus.outputs.cache-hit != 'true'
+        run: |
+          git clone --depth 1 --branch ${{ matrix.corpus.ref }} \
+            ${{ matrix.corpus.repo }} \
+            .eval-corpus/${{ matrix.corpus.name }}
+
+      # No-compromise guard: the committed ground truth must be exactly what a
+      # fresh conversion of the curated manifest produces *against this corpus*.
+      # manifest_gt_convert.py hard-errors on any labelled path that no longer
+      # exists in the clone (corpus drift / typo); the diff below catches a
+      # stale committed JSON.  For the RustSec negative control the manifest
+      # carries `negative_control = true` and zero entries, so the converter
+      # emits an empty `[]` — still validated against the real clone.
+      - name: Verify ground truth is in sync with the pinned corpus
+        run: |
+          python3 tests/eval_corpus/manifest_gt_convert.py \
+            --manifest tests/eval_corpus/ground_truth/${{ matrix.corpus.manifest }} \
+            --corpus-dir .eval-corpus/${{ matrix.corpus.name }} \
+            --output /tmp/${{ matrix.corpus.name }}_gt_regen.json
+          python3 - <<'PY'
+          import json, sys
+          name = "${{ matrix.corpus.ground_truth }}"
+          committed = json.load(open(f"tests/eval_corpus/ground_truth/{name}"))
+          regen = json.load(open("/tmp/${{ matrix.corpus.name }}_gt_regen.json"))
+          if committed != regen:
+              sys.exit("committed ground truth diverges from a fresh conversion of "
+                       "the manifest against the pinned corpus; regenerate with "
+                       "manifest_gt_convert.py")
+          print(f"ground truth in sync: {len(committed)} records")
+          PY
+
+      - name: eval-corpus harness regression tests
+        run: |
+          python3 tests/eval_corpus/test_tabulate_regression.py
+          python3 tests/eval_corpus/test_manifest_gt_convert.py
+
+      - name: Gate 8 — ${{ matrix.corpus.name }} acceptance
+        run: |
+          export ${{ matrix.corpus.env }}="${{ github.workspace }}/.eval-corpus/${{ matrix.corpus.name }}"
+          scripts/m7_ship_gate.sh --sets ${{ matrix.corpus.name }}
diff --git a/scripts/m7_ship_gate.sh b/scripts/m7_ship_gate.sh
index 7b8a0c28..b41ee493 100755
--- a/scripts/m7_ship_gate.sh
+++ b/scripts/m7_ship_gate.sh
@@ -8,6 +8,8 @@
 #   scripts/m7_ship_gate.sh --sets owasp        # Java OWASP corpus only
 #   scripts/m7_ship_gate.sh --sets jsts         # NodeGoat + Juice Shop only
 #   scripts/m7_ship_gate.sh --sets nodegoat     # one JS/TS corpus only
+#   scripts/m7_ship_gate.sh --sets polyglot     # RailsGoat+DVWA+DVPWA+gosec+RustSec
+#   scripts/m7_ship_gate.sh --sets railsgoat    # one polyglot corpus only
 #
 # Gate map (kept in sync with .pitboss/play/plan.md track M.7):
 #   Gate 1: Static-only scan is green on `tests/benchmark/corpus`.
@@ -37,13 +39,21 @@
 #           (NYX_JSTS_FLOOR_CAPS empty by default).  Each corpus row
 #           self-skips unless its NYX_NODEGOAT_CORPUS / NYX_JUICESHOP_CORPUS
 #           points at a real checkout.
+#   Gate 8: Polyglot real-corpus acceptance (Track R.2 / Phase 29).  OWASP
+#           RailsGoat (Rails, .rb), DVWA (PHP), DVPWA (aiohttp, .py), gosec
+#           (Go) and the RustSec advisory-db (Rust negative control), one
+#           row per corpus.  Same shape as Gate 7: wall-clock budget + the
+#           per-(cap,lang) budget hard-enforced; per-cap confirmed/precision/
+#           recall report-only (NYX_POLYGLOT_FLOOR_CAPS empty by default).
+#           Each row self-skips unless its NYX_<NAME>_CORPUS points at a real
+#           checkout.
 
 set -euo pipefail
 
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 cd "${REPO_ROOT}"
 
-GATES="1,2,3,4,5,6,7"
+GATES="1,2,3,4,5,6,7,8"
 SETS=""
 
 while [[ $# -gt 0 ]]; do
@@ -71,9 +81,10 @@ done
 # `jsts` (both JS/TS corpora) / `nodegoat` / `juiceshop` -> Gate 7, with the
 # corpus name passed through so Gate 7 runs only the requested row.
 case "${SETS}" in
-    owasp)                    GATES="6" ;;
-    jsts|nodegoat|juiceshop)  GATES="7" ;;
-    "")                       ;;  # no --sets: run the requested --gates
+    owasp)                                              GATES="6" ;;
+    jsts|nodegoat|juiceshop)                            GATES="7" ;;
+    polyglot|railsgoat|dvwa|dvpwa|gosec|rustsec)        GATES="8" ;;
+    "")                                                 ;;  # no --sets: run the requested --gates
     *)                        echo "unknown --sets: ${SETS}" >&2; exit 2 ;;
 esac
 
@@ -308,34 +319,31 @@ PY
     echo "  PASS"
 }
 
-# ── Gate 7: JS/TS real-corpus acceptance (NodeGoat + Juice Shop) ──────────────
-
-# Phase 28 (Track R.1) mirror of Gate 6 for the JS/TS corpora.  Same
-# wall-clock split (10 min dev reference / 15 min CI) and the same
-# report-only-by-default floor policy: NYX_JSTS_FLOOR_CAPS is empty, so the
-# per-cap confirmed-rate / precision / recall numbers are published but gate
-# nothing, while the per-(cap,lang) budget (unsupported_rate,
-# false_confirmed_rate) is hard-enforced.  Promote a cap into the floor set
-# once it starts Confirming end to end.
-GATE7_WALLCLOCK_BUDGET="${NYX_JSTS_WALLCLOCK_BUDGET_SECONDS:-900}"
-GATE7_CONFIRMED_RATE_TARGET="${NYX_JSTS_CONFIRMED_RATE_TARGET:-0.40}"
-GATE7_PRECISION_TARGET="${NYX_JSTS_PRECISION_TARGET:-0.85}"
-GATE7_RECALL_TARGET="${NYX_JSTS_RECALL_TARGET:-0.40}"
-GATE7_FLOOR_CAPS="${NYX_JSTS_FLOOR_CAPS:-}"
-GATE7_BUDGET="${NYX_JSTS_BUDGET:-${REPO_ROOT}/tests/eval_corpus/budget.toml}"
+# ── Shared real-corpus acceptance runner (Gates 7 + 8) ────────────────────────
 
 # Run one real-corpus `--verify` row: scan under a wall-clock guard,
 # tabulate against the committed ground truth, enforce the per-cell budget,
-# publish (or, when floor caps are set, enforce) the per-cap floors.
-#   $1 label  $2 corpus dir  $3 ground-truth json
+# publish (or, when floor caps are set, enforce) the per-cap floors.  Every
+# random source nyx uses is seeded from spec_hash, so reruns are
+# deterministic.  Generic across gates — all gate-specific knobs are passed
+# in so Gate 7 (JS/TS) and Gate 8 (polyglot) share one code path.
+#   $1 label        $2 corpus dir       $3 ground-truth json
+#   $4 wallclock(s) $5 budget.toml      $6 floor caps (may be empty)
+#   $7 confirmed target  $8 precision target  $9 recall target
+#   $10 floor-unset hint (e.g. "NYX_POLYGLOT_FLOOR_CAPS unset")
+#   $11 lang filter (may be empty) — scope tabulation to one language so
+#       incidental other-language assets (vendored JS in a Rails/aiohttp app)
+#       do not pollute the corpus's per-cap metrics
 # Returns 0 on pass, 1 on fail.  Caller decides skip.
-_gate7_run_corpus() {
-    local label="$1" corpus="$2" gt="$3"
-    local scan_report="/tmp/m7_gate7_${label}_scan.json"
-    local results_report="/tmp/m7_gate7_${label}_results.json"
-    local wallclock_report="/tmp/m7_gate7_${label}_wallclock.txt"
-    local gate_home="${TMPDIR:-/tmp}/nyx_m7_gate7_${label}_home"
-    local gate_build_pool="${TMPDIR:-/tmp}/nyx_m7_gate7_${label}_build_pool"
+_run_corpus_acceptance() {
+    local label="$1" corpus="$2" gt="$3" wallclock_budget="$4" budget_file="$5"
+    local floor_caps="$6" confirmed_target="$7" precision_target="$8"
+    local recall_target="$9" floor_hint="${10}" lang_filter="${11:-}"
+    local scan_report="/tmp/m7_corpus_${label}_scan.json"
+    local results_report="/tmp/m7_corpus_${label}_results.json"
+    local wallclock_report="/tmp/m7_corpus_${label}_wallclock.txt"
+    local gate_home="${TMPDIR:-/tmp}/nyx_m7_corpus_${label}_home"
+    local gate_build_pool="${TMPDIR:-/tmp}/nyx_m7_corpus_${label}_build_pool"
     local wallclock
 
     mkdir -p "${gate_home}" "${gate_build_pool}"
@@ -344,7 +352,7 @@ _gate7_run_corpus() {
     set +e
     HOME="${gate_home}" \
     NYX_BUILD_POOL_DIR="${gate_build_pool}" \
-    python3 - "${GATE7_WALLCLOCK_BUDGET}" "${scan_report}" "${wallclock_report}" \
+    python3 - "${wallclock_budget}" "${scan_report}" "${wallclock_report}" \
         "${REPO_ROOT}/target/release/nyx" scan \
         --verify \
         --index off \
@@ -375,9 +383,9 @@ sys.exit(rc)
 PY
     local nyx_exit=$?
     set -e
-    wallclock="$(cat "${wallclock_report}" 2>/dev/null || printf "%s" "${GATE7_WALLCLOCK_BUDGET}")"
+    wallclock="$(cat "${wallclock_report}" 2>/dev/null || printf "%s" "${wallclock_budget}")"
 
-    echo "    ${label} verify wall-clock: ${wallclock}s (budget ${GATE7_WALLCLOCK_BUDGET}s)"
+    echo "    ${label} verify wall-clock: ${wallclock}s (budget ${wallclock_budget}s)"
 
     if [[ ${nyx_exit} -eq 124 ]]; then
         echo "    FAIL: ${label} scan exceeded wall-clock budget"
@@ -391,38 +399,60 @@ PY
         echo "    FAIL: ${label} scan produced no JSON report"
         return 1
     fi
-    awk -v w="${wallclock}" -v b="${GATE7_WALLCLOCK_BUDGET}" \
+    awk -v w="${wallclock}" -v b="${wallclock_budget}" \
         'BEGIN { if (w+0 > b+0) exit 1 }' \
         || { echo "    FAIL: ${label} wall-clock exceeds budget"; return 1; }
 
     echo "[]" > "${results_report}"
-    python3 "${REPO_ROOT}/tests/eval_corpus/tabulate.py" \
-        --label "${label}" \
-        --scan "${scan_report}" \
-        --ground-truth "${gt}" \
-        --append "${results_report}" \
+    local -a tabulate_args=(
+        --label "${label}"
+        --scan "${scan_report}"
+        --ground-truth "${gt}"
+        --append "${results_report}"
+    )
+    if [[ -n "${lang_filter}" ]]; then
+        tabulate_args+=(--lang "${lang_filter}")
+        echo "    scoping tabulation to language(s): ${lang_filter}"
+    fi
+    python3 "${REPO_ROOT}/tests/eval_corpus/tabulate.py" "${tabulate_args[@]}" \
         || { echo "    FAIL: ${label} result tabulation failed"; return 1; }
 
     local -a report_args=(
         --results "${results_report}"
-        --budget "${GATE7_BUDGET}"
+        --budget "${budget_file}"
     )
-    if [[ -n "${GATE7_FLOOR_CAPS}" ]]; then
+    if [[ -n "${floor_caps}" ]]; then
         report_args+=(
-            --floor-caps "${GATE7_FLOOR_CAPS}"
-            --min-confirmed-rate "${GATE7_CONFIRMED_RATE_TARGET}"
-            --min-precision "${GATE7_PRECISION_TARGET}"
-            --min-recall "${GATE7_RECALL_TARGET}"
+            --floor-caps "${floor_caps}"
+            --min-confirmed-rate "${confirmed_target}"
+            --min-precision "${precision_target}"
+            --min-recall "${recall_target}"
         )
-        echo "    enforcing per-cap floors (confirmed >= ${GATE7_CONFIRMED_RATE_TARGET}, precision >= ${GATE7_PRECISION_TARGET}, recall >= ${GATE7_RECALL_TARGET}) on: ${GATE7_FLOOR_CAPS}"
+        echo "    enforcing per-cap floors (confirmed >= ${confirmed_target}, precision >= ${precision_target}, recall >= ${recall_target}) on: ${floor_caps}"
     else
-        echo "    per-cap confirmed/precision/recall: report-only (NYX_JSTS_FLOOR_CAPS unset)"
+        echo "    per-cap confirmed/precision/recall: report-only (${floor_hint})"
     fi
     python3 "${REPO_ROOT}/tests/eval_corpus/report.py" "${report_args[@]}" \
         || { echo "    FAIL: ${label} per-cell budget exceeded or a gated per-cap floor missed"; return 1; }
     return 0
 }
 
+# ── Gate 7: JS/TS real-corpus acceptance (NodeGoat + Juice Shop) ──────────────
+
+# Phase 28 (Track R.1) mirror of Gate 6 for the JS/TS corpora.  Same
+# wall-clock split (10 min dev reference / 15 min CI) and the same
+# report-only-by-default floor policy: NYX_JSTS_FLOOR_CAPS is empty, so the
+# per-cap confirmed-rate / precision / recall numbers are published but gate
+# nothing, while the per-(cap,lang) budget (unsupported_rate,
+# false_confirmed_rate) is hard-enforced.  Promote a cap into the floor set
+# once it starts Confirming end to end.
+GATE7_WALLCLOCK_BUDGET="${NYX_JSTS_WALLCLOCK_BUDGET_SECONDS:-900}"
+GATE7_CONFIRMED_RATE_TARGET="${NYX_JSTS_CONFIRMED_RATE_TARGET:-0.40}"
+GATE7_PRECISION_TARGET="${NYX_JSTS_PRECISION_TARGET:-0.85}"
+GATE7_RECALL_TARGET="${NYX_JSTS_RECALL_TARGET:-0.40}"
+GATE7_FLOOR_CAPS="${NYX_JSTS_FLOOR_CAPS:-}"
+GATE7_BUDGET="${NYX_JSTS_BUDGET:-${REPO_ROOT}/tests/eval_corpus/budget.toml}"
+
 gate_7_jsts_scale() {
     echo "── Gate 7: JS/TS real-corpus (NodeGoat + Juice Shop) verify acceptance ──"
     cargo build --release --quiet --features dynamic
@@ -447,8 +477,13 @@ gate_7_jsts_scale() {
         fi
         any_ran=1
         echo "  ── ${name} (${corpus}) ──"
-        if _gate7_run_corpus "${name}" "${corpus}" \
-                "${REPO_ROOT}/tests/eval_corpus/ground_truth/${gtfile}"; then
+        # No --lang scope: NodeGoat/Juice Shop are single-language (js/ts), so
+        # there is no cross-language asset noise to filter (unchanged Gate 7).
+        if _run_corpus_acceptance "${name}" "${corpus}" \
+                "${REPO_ROOT}/tests/eval_corpus/ground_truth/${gtfile}" \
+                "${GATE7_WALLCLOCK_BUDGET}" "${GATE7_BUDGET}" "${GATE7_FLOOR_CAPS}" \
+                "${GATE7_CONFIRMED_RATE_TARGET}" "${GATE7_PRECISION_TARGET}" \
+                "${GATE7_RECALL_TARGET}" "NYX_JSTS_FLOOR_CAPS unset" ""; then
             echo "  PASS ${name}"
         else
             any_failed=1
@@ -464,6 +499,76 @@ gate_7_jsts_scale() {
     echo "  PASS"
 }
 
+# ── Gate 8: Polyglot real-corpus acceptance (Track R.2 / Phase 29) ────────────
+
+# RailsGoat (Rails, .rb) + DVWA (PHP) + DVPWA (aiohttp, .py) + gosec (Go) +
+# the RustSec advisory-db (Rust negative control).  Same wall-clock split and
+# the same report-only-by-default floor policy as Gates 6/7: the per-(cap,lang)
+# budget in tests/eval_corpus/budget.toml is hard-enforced, while per-cap
+# confirmed-rate / precision / recall are published but gate nothing until
+# NYX_POLYGLOT_FLOOR_CAPS names a cap.  Each row self-skips unless its
+# corpus env var points at a real checkout.  The RustSec row is a NEGATIVE
+# CONTROL: advisory-db ships advisory metadata, not vulnerable source, so its
+# ground truth is empty by construction and the row asserts nyx Confirms
+# nothing there (false_confirmed_rate guard).
+GATE8_WALLCLOCK_BUDGET="${NYX_POLYGLOT_WALLCLOCK_BUDGET_SECONDS:-900}"
+GATE8_CONFIRMED_RATE_TARGET="${NYX_POLYGLOT_CONFIRMED_RATE_TARGET:-0.40}"
+GATE8_PRECISION_TARGET="${NYX_POLYGLOT_PRECISION_TARGET:-0.85}"
+GATE8_RECALL_TARGET="${NYX_POLYGLOT_RECALL_TARGET:-0.40}"
+GATE8_FLOOR_CAPS="${NYX_POLYGLOT_FLOOR_CAPS:-}"
+GATE8_BUDGET="${NYX_POLYGLOT_BUDGET:-${REPO_ROOT}/tests/eval_corpus/budget.toml}"
+
+gate_8_polyglot_scale() {
+    echo "── Gate 8: polyglot real-corpus (RailsGoat/DVWA/DVPWA/gosec/RustSec) verify acceptance ──"
+    cargo build --release --quiet --features dynamic
+
+    # name : env var holding the corpus dir : committed ground-truth file :
+    # target language (tabulation is scoped to it so incidental other-language
+    # assets — e.g. vendored JS in the Rails / aiohttp apps — do not pollute
+    # the corpus's per-cap metrics).
+    local rows=(
+        "railsgoat:NYX_RAILSGOAT_CORPUS:railsgoat.json:ruby"
+        "dvwa:NYX_DVWA_CORPUS:dvwa.json:php"
+        "dvpwa:NYX_DVPWA_CORPUS:dvpwa.json:python"
+        "gosec:NYX_GOSEC_CORPUS:gosec.json:go"
+        "rustsec:NYX_RUSTSEC_CORPUS:rustsec.json:rust"
+    )
+    local any_ran=0 any_failed=0
+    for row in "${rows[@]}"; do
+        local name envvar gtfile lang
+        IFS=: read -r name envvar gtfile lang <<<"${row}"
+        # When --sets names a single corpus, only run that row.
+        if [[ -n "${SETS}" && "${SETS}" != "polyglot" && "${SETS}" != "${name}" ]]; then
+            continue
+        fi
+        local corpus="${!envvar:-}"
+        if [[ -z "${corpus}" || ! -d "${corpus}" ]]; then
+            echo "  SKIP ${name}: set ${envvar} to a checkout to run this row."
+            continue
+        fi
+        any_ran=1
+        echo "  ── ${name} (${corpus}) ──"
+        if _run_corpus_acceptance "${name}" "${corpus}" \
+                "${REPO_ROOT}/tests/eval_corpus/ground_truth/${gtfile}" \
+                "${GATE8_WALLCLOCK_BUDGET}" "${GATE8_BUDGET}" "${GATE8_FLOOR_CAPS}" \
+                "${GATE8_CONFIRMED_RATE_TARGET}" "${GATE8_PRECISION_TARGET}" \
+                "${GATE8_RECALL_TARGET}" "NYX_POLYGLOT_FLOOR_CAPS unset" "${lang}"; then
+            echo "  PASS ${name}"
+        else
+            any_failed=1
+        fi
+    done
+
+    if [[ ${any_ran} -eq 0 ]]; then
+        echo "  SKIP: no polyglot corpus configured (set NYX_RAILSGOAT_CORPUS /"
+        echo "        NYX_DVWA_CORPUS / NYX_DVPWA_CORPUS / NYX_GOSEC_CORPUS / NYX_RUSTSEC_CORPUS)."
+        echo "        (Gate 8 is Phase 29's headline acceptance for the polyglot real corpora.)"
+        return 0
+    fi
+    [[ ${any_failed} -eq 0 ]] || return 1
+    echo "  PASS"
+}
+
 # ── Driver ────────────────────────────────────────────────────────────────────
 
 declare -a FAILED=()
@@ -483,6 +588,7 @@ run_gate 4 sarif_schema
 run_gate 5 layering
 run_gate 6 owasp_scale
 run_gate 7 jsts_scale
+run_gate 8 polyglot_scale
 
 if [[ ${#FAILED[@]} -gt 0 ]]; then
     echo
diff --git a/tests/eval_corpus/budget.toml b/tests/eval_corpus/budget.toml
index 340da270..6a213134 100644
--- a/tests/eval_corpus/budget.toml
+++ b/tests/eval_corpus/budget.toml
@@ -200,3 +200,153 @@ cap = "crypto"
 lang = "typescript"
 unsupported_rate     = 0.20
 false_confirmed_rate = 0.02
+
+# ── Polyglot real corpora (Ruby/PHP/Python/Go/Rust) — Track R.2 ──────────────
+#
+# Phase 29 wires five more intentionally-vulnerable real corpora, one per
+# remaining language family, into the same acceptance machinery as OWASP /
+# NodeGoat / Juice Shop:
+#
+#   * railsgoat  — OWASP RailsGoat (Rails, .rb)
+#   * dvwa       — Damn Vulnerable Web Application (PHP); ships graded
+#                  source variants, so low.php = vuln and impossible.php =
+#                  benign control — real vuln/benign PAIRS like OWASP.
+#   * dvpwa      — Damn Vulnerable Python Web App (aiohttp, .py); its
+#                  parameterized DAO siblings are benign controls for the
+#                  one `%`-formatted SQL sink.
+#   * gosec      — the Go SAST tool's own repo; the scannable, `// want`-
+#                  annotated sample under goanalysis/testdata is the curated
+#                  ground truth (its embedded-string rule samples are not
+#                  scannable, so they are unlabelled).
+#   * rustsec    — RustSec advisory-db: a NEGATIVE CONTROL.  It ships
+#                  advisory metadata, not vulnerable .rs source, so its
+#                  ground truth is empty by construction; the row asserts the
+#                  Rust scan/verify path runs at scale within wall-clock and
+#                  Confirms NOTHING (any Confirmed Rust finding there is a
+#                  false confirm and trips the default false_confirmed_rate).
+#
+# Each row is gated with the SAME policy as Gates 6/7 (scripts/m7_ship_gate.sh
+# Gate 8): wall-clock + the per-(cap,lang) budget below are HARD-enforced;
+# per-cap confirmed-rate / precision / recall are published report-only
+# (NYX_POLYGLOT_FLOOR_CAPS empty by default).  Because each corpus targets a
+# single language, Gate 8 scopes tabulation to that language (tabulate.py
+# --lang), so the vendored third-party JavaScript these Ruby/Python apps
+# bundle (bootstrap-colorpicker, materialize, …) — which nyx confirms as
+# prototype_pollution — does not pollute the corpus's per-cap metrics.  Those
+# JS findings are still emitted; they are simply out of scope for a Ruby /
+# Python corpus.
+#
+# Calibrated against the pinned corpora (nyx HEAD of the Phase 29 branch,
+# 2026-05-31) with `nyx scan --verify --index off`.  Measured frontier
+# (target-language scope): every curated cell sits at <= the headline maxima
+# below EXCEPT cmdi, where every finding carries a SHELL_ESCAPE sanitizer cap
+# and is therefore routed to Unsupported(SoundOracleUnavailable) — the same
+# no-sound-oracle treatment OWASP's crypto/auth cells get.  RailsGoat's
+# deserialize (Marshal.load) and redirect (open redirect) cells Confirm end to
+# end with zero false confirms — the first real polyglot confirms.
+
+# railsgoat (ruby): caps with a ground-truth label in railsgoat.manifest.toml.
+[[cell]]
+cap = "auth"
+lang = "ruby"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+[[cell]]
+cap = "crypto"
+lang = "ruby"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+[[cell]]
+cap = "deserialize"
+lang = "ruby"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+[[cell]]
+cap = "redirect"
+lang = "ruby"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+[[cell]]
+cap = "path_traversal"
+lang = "ruby"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+# cmdi/ruby is incidental (RailsGoat's `self.try(params[:graph])` reflection
+# sink); the lone finding carries a SHELL_ESCAPE sanitizer cap and routes to
+# Unsupported(SoundOracleUnavailable), so unsupported_rate is locked at the
+# measured frontier (1/1).  The false-confirm guard stays at the headline 2%.
+[[cell]]
+cap = "cmdi"
+lang = "ruby"
+unsupported_rate     = 1.00
+false_confirmed_rate = 0.02
+
+# dvwa (php): caps with a ground-truth label in dvwa.manifest.toml.
+[[cell]]
+cap = "sqli"
+lang = "php"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+[[cell]]
+cap = "redirect"
+lang = "php"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+[[cell]]
+cap = "header_injection"
+lang = "php"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+# cmdi/php: DVWA's ping handlers reach shell_exec through a SHELL_ESCAPE
+# sanitizer cap, so ~69% of the cell's findings route to
+# Unsupported(SoundOracleUnavailable).  unsupported_rate is locked to that
+# frontier with margin (a regression above 75% fails); false-confirm at 2%.
+[[cell]]
+cap = "cmdi"
+lang = "php"
+unsupported_rate     = 0.75
+false_confirmed_rate = 0.02
+
+# dvpwa (python): caps with a ground-truth label in dvpwa.manifest.toml.
+[[cell]]
+cap = "sqli"
+lang = "python"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+[[cell]]
+cap = "crypto"
+lang = "python"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+[[cell]]
+cap = "auth"
+lang = "python"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+# gosec (go): caps with a ground-truth label in gosec.manifest.toml.
+[[cell]]
+cap = "crypto"
+lang = "go"
+unsupported_rate     = 0.20
+false_confirmed_rate = 0.02
+
+# cmdi/go: the goanalysis/testdata exec.Command sample reaches the sink
+# through a SHELL_ESCAPE sanitizer cap, so every cmdi/go finding routes to
+# Unsupported(SoundOracleUnavailable).  unsupported_rate locked to the
+# measured frontier (3/3); false-confirm at the headline 2%.
+[[cell]]
+cap = "cmdi"
+lang = "go"
+unsupported_rate     = 1.00
+false_confirmed_rate = 0.02
diff --git a/tests/eval_corpus/ground_truth/README.md b/tests/eval_corpus/ground_truth/README.md
index 663a0be6..3e09583a 100644
--- a/tests/eval_corpus/ground_truth/README.md
+++ b/tests/eval_corpus/ground_truth/README.md
@@ -69,3 +69,38 @@ known vulns) is the meaningful metric; precision vs this partial ground
 truth is informational. Gate 7 publishes per-cap precision/recall/confirmed
 report-only by default (`NYX_JSTS_FLOOR_CAPS` empty), matching the OWASP
 gate.
+
+## Polyglot real corpora (Ruby/PHP/Python/Go/Rust — Track R.2)
+
+Phase 29 wires the remaining language families into the same machinery, one
+corpus per family, each with a curated `*.manifest.toml` → committed `*.json`:
+
+- `railsgoat.{manifest.toml,json}` — OWASP RailsGoat (Rails, `.rb`).
+- `dvwa.{manifest.toml,json}` — Damn Vulnerable Web Application (PHP). DVWA
+  ships graded source variants (`source/{low,impossible}.php`), so this is
+  the one Track R corpus besides OWASP with real vuln/benign **pairs**
+  (`low.php` = vuln, `impossible.php` = benign control) — precision is
+  meaningful here, not just informational.
+- `dvpwa.{manifest.toml,json}` — Damn Vulnerable Python Web App (aiohttp,
+  `.py`). Its parameterized DAO siblings are benign controls for the one
+  `%`-formatted SQL sink.
+- `gosec.{manifest.toml,json}` — the gosec Go SAST tool repo; the scannable,
+  `// want`-annotated sample under `goanalysis/testdata` is the curated
+  ground truth (gosec's string-embedded rule samples are not scannable, so
+  they are deliberately unlabelled).
+- `rustsec.{manifest.toml,json}` — RustSec advisory-db, a **negative
+  control**. advisory-db ships advisory metadata, not vulnerable `.rs`
+  source, so its committed ground truth is empty (`[]`) by construction. The
+  manifest sets `negative_control = true` (mutually exclusive with
+  `[[entry]]` tables); `manifest_gt_convert.py` emits the empty JSON and the
+  row asserts the Rust scan/verify path runs at scale within wall-clock and
+  Confirms nothing there (any Confirmed Rust finding is a false confirm).
+
+These are converted, validated and asserted-in-sync exactly like NodeGoat /
+Juice Shop (the `polyglot` job in `.github/workflows/eval.yml`). Because each
+corpus targets a single language, Gate 8 scopes tabulation to that language
+(`tabulate.py --lang`) so the vendored third-party JavaScript these Ruby /
+Python apps bundle does not pollute their per-cap metrics. Gate 8 publishes
+per-cap precision/recall/confirmed report-only by default
+(`NYX_POLYGLOT_FLOOR_CAPS` empty), matching the OWASP and JS/TS gates. See
+`tests/eval_corpus/budget.toml` for the per-(cap,lang) gate policy.
diff --git a/tests/eval_corpus/ground_truth/dvpwa.json b/tests/eval_corpus/ground_truth/dvpwa.json
new file mode 100644
index 00000000..f1f764eb
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/dvpwa.json
@@ -0,0 +1,38 @@
+[
+  {
+    "path": "sqli/dao/course.py",
+    "line": 0,
+    "cap": "sqli",
+    "vuln": false
+  },
+  {
+    "path": "sqli/dao/mark.py",
+    "line": 0,
+    "cap": "sqli",
+    "vuln": false
+  },
+  {
+    "path": "sqli/dao/review.py",
+    "line": 0,
+    "cap": "sqli",
+    "vuln": false
+  },
+  {
+    "path": "sqli/dao/student.py",
+    "line": 0,
+    "cap": "sqli",
+    "vuln": true
+  },
+  {
+    "path": "sqli/dao/user.py",
+    "line": 0,
+    "cap": "crypto",
+    "vuln": true
+  },
+  {
+    "path": "sqli/views.py",
+    "line": 0,
+    "cap": "auth",
+    "vuln": true
+  }
+]
diff --git a/tests/eval_corpus/ground_truth/dvpwa.manifest.toml b/tests/eval_corpus/ground_truth/dvpwa.manifest.toml
new file mode 100644
index 00000000..af005801
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/dvpwa.manifest.toml
@@ -0,0 +1,70 @@
+# DVPWA (Damn Vulnerable Python Web Application) — curated ground-truth
+# manifest (Phase 29, Track R.2).
+#
+# DVPWA is an intentionally-vulnerable aiohttp app whose headline flaw is
+# SQL injection (the package is literally named `sqli`).  It ships no
+# machine-readable per-file labels, so this manifest IS the authoritative
+# source.  Its DAO layer is convenient: one method builds a query with
+# Python `%` string-formatting (the injectable sink) while its siblings use
+# proper parameterized `cur.execute(q, params)` — so the parameterized DAOs
+# serve as genuine benign controls (vuln = false) for the sqli cell, making
+# precision there meaningful, not just informational.
+#
+# tests/eval_corpus/manifest_gt_convert.py turns this into the committed
+# ground_truth/dvpwa.json.  CI regenerates it against a fresh clone of the
+# pinned ref and asserts byte-equality; the converter HARD-ERRORS on any
+# path that no longer exists, so a corpus bump that moves a DAO fails the
+# job loudly rather than silently dropping recall.
+#
+# `cap` is a nyx cap label (tabulate.py), aligned to how nyx classifies each
+# sink (the request-scoped ownership lookups in views.py surface as `auth`).
+# `path` is relative to the DVPWA clone root, POSIX separators.  Lang is
+# inferred from the extension (.py -> python).  See
+# tests/eval_corpus/budget.toml for the gate policy on these cells.
+
+corpus = "dvpwa"
+upstream = "https://github.com/anxolerd/dvpwa"
+# DVPWA publishes no release tags; the eval job pins the default branch via
+# the CI cache key (clone HEAD a1d8f89fac2e57093189853c6527c2b01fc1d9c1).
+# The sqli/ package layout has been stable; re-validate if the cache key is
+# bumped.
+pinned_ref = "master"
+
+# ── SQL injection (sqli) — one injectable sink + parameterized controls ──────
+[[entry]]
+path = "sqli/dao/student.py"
+cap = "sqli"
+vuln = true
+note = "Student.create builds the INSERT with Python `%` formatting (\"... VALUES ('%(name)s')\" % {'name': name}) on the request-supplied student name, then cur.execute(q) — SQL injection."
+
+[[entry]]
+path = "sqli/dao/course.py"
+cap = "sqli"
+vuln = false
+note = "benign control: every Course query uses parameterized cur.execute(q, params) / VALUES (%(title)s, %(description)s) — not injectable."
+
+[[entry]]
+path = "sqli/dao/review.py"
+cap = "sqli"
+vuln = false
+note = "benign control: Review.create / get_for_course bind via cur.execute(q, params) with %(course_id)s / %s placeholders — parameterized."
+
+[[entry]]
+path = "sqli/dao/mark.py"
+cap = "sqli"
+vuln = false
+note = "benign control: Mark.create / get_for_student bind via parameterized cur.execute(q, params) — not injectable."
+
+# ── Weak crypto (crypto) ─────────────────────────────────────────────────────
+[[entry]]
+path = "sqli/dao/user.py"
+cap = "crypto"
+vuln = true
+note = "User.check_password compares against md5(password).hexdigest() — unsalted MD5 for credential storage (weak cryptography)."
+
+# ── Broken access control (auth) ─────────────────────────────────────────────
+[[entry]]
+path = "sqli/views.py"
+cap = "auth"
+vuln = true
+note = "request handlers resolve the acting user from a client-controlled session id and act on objects without an ownership/authorization check — broken access control."
diff --git a/tests/eval_corpus/ground_truth/dvwa.json b/tests/eval_corpus/ground_truth/dvwa.json
new file mode 100644
index 00000000..3431ff5a
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/dvwa.json
@@ -0,0 +1,50 @@
+[
+  {
+    "path": "vulnerabilities/exec/source/impossible.php",
+    "line": 0,
+    "cap": "cmdi",
+    "vuln": false
+  },
+  {
+    "path": "vulnerabilities/exec/source/low.php",
+    "line": 0,
+    "cap": "cmdi",
+    "vuln": true
+  },
+  {
+    "path": "vulnerabilities/open_redirect/source/impossible.php",
+    "line": 0,
+    "cap": "header_injection",
+    "vuln": false
+  },
+  {
+    "path": "vulnerabilities/open_redirect/source/impossible.php",
+    "line": 0,
+    "cap": "redirect",
+    "vuln": false
+  },
+  {
+    "path": "vulnerabilities/open_redirect/source/low.php",
+    "line": 0,
+    "cap": "header_injection",
+    "vuln": true
+  },
+  {
+    "path": "vulnerabilities/open_redirect/source/low.php",
+    "line": 0,
+    "cap": "redirect",
+    "vuln": true
+  },
+  {
+    "path": "vulnerabilities/sqli/source/impossible.php",
+    "line": 0,
+    "cap": "sqli",
+    "vuln": false
+  },
+  {
+    "path": "vulnerabilities/sqli/source/low.php",
+    "line": 0,
+    "cap": "sqli",
+    "vuln": true
+  }
+]
diff --git a/tests/eval_corpus/ground_truth/dvwa.manifest.toml b/tests/eval_corpus/ground_truth/dvwa.manifest.toml
new file mode 100644
index 00000000..9cab6759
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/dvwa.manifest.toml
@@ -0,0 +1,84 @@
+# DVWA (Damn Vulnerable Web Application) — curated ground-truth manifest
+# (Phase 29, Track R.2).
+#
+# DVWA is an intentionally-vulnerable PHP app.  Unlike the other Track R
+# apps it ships its vulnerabilities as graded source variants under
+# vulnerabilities/<module>/source/{low,medium,high,impossible}.php, where
+# `low.php` is the textbook-vulnerable handler and `impossible.php` is the
+# hardened, secure rewrite of the SAME sink.  That gives DVWA real
+# vuln/benign PAIRS (low = vuln, impossible = benign control) the way OWASP
+# Benchmark does — so precision against this manifest is meaningful, not
+# just informational: a Confirmed finding on an `impossible.php` control is
+# a genuine false confirm.
+#
+# tests/eval_corpus/manifest_gt_convert.py turns this into the committed
+# ground_truth/dvwa.json.  CI regenerates it against a fresh clone of the
+# pinned tag and asserts byte-equality; the converter HARD-ERRORS on any
+# path that no longer exists, so a DVWA bump that restructures a module
+# fails loudly rather than silently dropping recall.  Re-pin `pinned_ref`
+# and re-validate the paths together.
+#
+# `cap` is a nyx cap label (tabulate.py), aligned to how nyx classifies the
+# sink.  `path` is relative to the DVWA clone root, POSIX separators.  Lang
+# is inferred from the extension (.php -> php).  See
+# tests/eval_corpus/budget.toml for the gate policy on these cells.
+
+corpus = "dvwa"
+upstream = "https://github.com/digininja/DVWA"
+# Pinned to release tag 2.5 (clone HEAD
+# a96943dc1f52f390ee5df72144660636c4b7dd06).  The
+# vulnerabilities/<module>/source/{low,impossible}.php layout has been stable
+# for years; re-validate if the tag is bumped.
+pinned_ref = "2.5"
+
+# ── SQL injection (sqli) ─────────────────────────────────────────────────────
+[[entry]]
+path = "vulnerabilities/sqli/source/low.php"
+cap = "sqli"
+vuln = true
+note = "id = $_REQUEST['id'] is concatenated straight into \"... WHERE user_id = '$id'\" and run via mysqli_query — classic SQL injection."
+
+[[entry]]
+path = "vulnerabilities/sqli/source/impossible.php"
+cap = "sqli"
+vuln = false
+note = "benign control: same query via PDO prepare + bindParam(:id, PDO::PARAM_INT) with is_numeric/intval validation — parameterized, not injectable."
+
+# ── OS command injection (cmdi) ──────────────────────────────────────────────
+[[entry]]
+path = "vulnerabilities/exec/source/low.php"
+cap = "cmdi"
+vuln = true
+note = "target = $_REQUEST['ip'] is concatenated into shell_exec('ping -c 4 ' . $target) with no validation — OS command injection."
+
+[[entry]]
+path = "vulnerabilities/exec/source/impossible.php"
+cap = "cmdi"
+vuln = false
+note = "benign control: the IP is split into 4 octets and each is_numeric-checked before being reassembled and passed to shell_exec — not injectable."
+
+# ── Open redirect (redirect) ─────────────────────────────────────────────────
+[[entry]]
+path = "vulnerabilities/open_redirect/source/low.php"
+cap = "redirect"
+vuln = true
+note = "header('location: ' . $_GET['redirect']) forwards to an unvalidated user-supplied URL — open redirect."
+
+[[entry]]
+path = "vulnerabilities/open_redirect/source/impossible.php"
+cap = "redirect"
+vuln = false
+note = "benign control: redirect target is chosen by an integer switch on is_numeric($_GET['redirect']) — no user-controlled URL reaches the Location header."
+
+# ── CRLF / HTTP header injection (header_injection) ──────────────────────────
+[[entry]]
+path = "vulnerabilities/open_redirect/source/low.php"
+cap = "header_injection"
+vuln = true
+note = "the same unvalidated $_GET['redirect'] flows into a raw header() call, so CRLF in the value splits/injects response headers — HTTP header injection."
+
+[[entry]]
+path = "vulnerabilities/open_redirect/source/impossible.php"
+cap = "header_injection"
+vuln = false
+note = "benign control: only a fixed, integer-selected target string reaches header() — no user bytes, so no CRLF injection."
diff --git a/tests/eval_corpus/ground_truth/gosec.json b/tests/eval_corpus/ground_truth/gosec.json
new file mode 100644
index 00000000..4467831b
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/gosec.json
@@ -0,0 +1,14 @@
+[
+  {
+    "path": "goanalysis/testdata/src/a/basic_output.go",
+    "line": 0,
+    "cap": "cmdi",
+    "vuln": true
+  },
+  {
+    "path": "goanalysis/testdata/src/a/basic_output.go",
+    "line": 0,
+    "cap": "crypto",
+    "vuln": true
+  }
+]
diff --git a/tests/eval_corpus/ground_truth/gosec.manifest.toml b/tests/eval_corpus/ground_truth/gosec.manifest.toml
new file mode 100644
index 00000000..a335d58c
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/gosec.manifest.toml
@@ -0,0 +1,42 @@
+# gosec — curated Go ground-truth manifest (Phase 29, Track R.2).
+#
+# gosec is the Go SAST tool; its repo doubles as the de-facto Go security
+# corpus.  Most of gosec's rule samples live as Go source embedded in
+# backtick string literals inside testutils/g*_samples.go — those are NOT
+# scannable by a taint analyzer (the vulnerable code is string data, not
+# real AST), so they are deliberately NOT labelled here.  gosec also ships a
+# small set of REAL, compilable sample programs under goanalysis/testdata
+# that carry the tool's OWN inline `// want 'GNNN ...'` expectations — that
+# is the authoritative, scannable ground truth this manifest pins.
+#
+# Because the eval scans the whole gosec checkout (the tool's own source
+# included), unlabelled findings are expected and are NOT false positives —
+# precision against this manifest is informational, recall on the curated
+# samples is the meaningful floor (same policy as the all-vulnerable apps;
+# see tests/eval_corpus/budget.toml).
+#
+# tests/eval_corpus/manifest_gt_convert.py turns this into the committed
+# ground_truth/gosec.json.  CI regenerates it against a fresh clone of the
+# pinned tag and asserts byte-equality; the converter HARD-ERRORS on any
+# path that no longer exists, so a gosec bump that moves the testdata fails
+# the job loudly.  `cap` is a nyx cap label (tabulate.py); `path` is relative
+# to the gosec clone root, POSIX separators; lang is inferred (.go -> go).
+
+corpus = "gosec"
+upstream = "https://github.com/securego/gosec"
+# Pinned to release tag v2.26.1 (clone HEAD
+# 4a3bd8af174872c778439083ded7adbf3747e770).  goanalysis/testdata/src/a/ has
+# been stable; re-validate if the tag is bumped.
+pinned_ref = "v2.26.1"
+
+[[entry]]
+path = "goanalysis/testdata/src/a/basic_output.go"
+cap = "cmdi"
+vuln = true
+note = "VulnerableFunction runs exec.Command(\"sh\", \"-c\", getUserInput()) — subprocess launched with a non-constant argument (gosec's own `// want G204 [CWE-78]` expectation)."
+
+[[entry]]
+path = "goanalysis/testdata/src/a/basic_output.go"
+cap = "crypto"
+vuln = true
+note = "VulnerableFunction imports crypto/md5 and calls md5.New() — weak cryptographic primitive (gosec's own `// want G401/G501` expectations)."
diff --git a/tests/eval_corpus/ground_truth/railsgoat.json b/tests/eval_corpus/ground_truth/railsgoat.json
new file mode 100644
index 00000000..e3bcc5d3
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/railsgoat.json
@@ -0,0 +1,56 @@
+[
+  {
+    "path": "app/controllers/admin_controller.rb",
+    "line": 0,
+    "cap": "auth",
+    "vuln": true
+  },
+  {
+    "path": "app/controllers/benefit_forms_controller.rb",
+    "line": 0,
+    "cap": "deserialize",
+    "vuln": true
+  },
+  {
+    "path": "app/controllers/benefit_forms_controller.rb",
+    "line": 0,
+    "cap": "path_traversal",
+    "vuln": true
+  },
+  {
+    "path": "app/controllers/messages_controller.rb",
+    "line": 0,
+    "cap": "auth",
+    "vuln": true
+  },
+  {
+    "path": "app/controllers/password_resets_controller.rb",
+    "line": 0,
+    "cap": "crypto",
+    "vuln": true
+  },
+  {
+    "path": "app/controllers/password_resets_controller.rb",
+    "line": 0,
+    "cap": "deserialize",
+    "vuln": true
+  },
+  {
+    "path": "app/controllers/sessions_controller.rb",
+    "line": 0,
+    "cap": "redirect",
+    "vuln": true
+  },
+  {
+    "path": "app/controllers/users_controller.rb",
+    "line": 0,
+    "cap": "auth",
+    "vuln": true
+  },
+  {
+    "path": "app/models/user.rb",
+    "line": 0,
+    "cap": "crypto",
+    "vuln": true
+  }
+]
diff --git a/tests/eval_corpus/ground_truth/railsgoat.manifest.toml b/tests/eval_corpus/ground_truth/railsgoat.manifest.toml
new file mode 100644
index 00000000..0f2609d8
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/railsgoat.manifest.toml
@@ -0,0 +1,88 @@
+# OWASP RailsGoat — curated vuln ground-truth manifest (Phase 29, Track R.2).
+#
+# RailsGoat is an intentionally-vulnerable Ruby on Rails app that maps the
+# OWASP Top 10 to concrete controllers/models.  Like NodeGoat / Juice Shop
+# (Phase 28) it ships no machine-readable per-file vuln labels, so this
+# manifest IS the authoritative source: one [[entry]] per known-vulnerable
+# location, curated from the project's own tutorial walk-throughs, each with
+# a `note` citing why.
+#
+# tests/eval_corpus/manifest_gt_convert.py turns this into the committed
+# ground_truth/railsgoat.json.  CI regenerates it against a fresh clone of
+# the pinned tag and asserts byte-equality, and the converter HARD-ERRORS on
+# any path that no longer exists in the corpus, so a RailsGoat bump that
+# moves a controller fails the eval job loudly rather than silently dropping
+# recall.  Update `pinned_ref` + the paths together when re-pinning.
+#
+# `cap` is a nyx cap label (tabulate.py); it is aligned with how nyx
+# classifies the sink in each file (e.g. a missing ownership check on a
+# direct-object lookup surfaces as `auth`, not `unauthorized_id`), so recall
+# (did nyx catch the canonical vuln) is meaningful.  `path` is relative to
+# the RailsGoat clone root, POSIX separators.  Lang is inferred from the
+# extension (.rb -> ruby).  All `vuln = true`: RailsGoat is all-vulnerable,
+# so there is no benign-control file to pair against — precision vs this
+# manifest is informational (an unlabelled finding may be a real uncurated
+# vuln), while recall is the meaningful floor.  See
+# tests/eval_corpus/budget.toml for how the gate treats these cells.
+
+corpus = "railsgoat"
+upstream = "https://github.com/OWASP/railsgoat"
+# Pinned to the stable Rails 5 release tag (clone HEAD
+# 0766ca80bf2d94acbde1dd4aaf7baf9b86afe4eb).  The app/controllers + app/models
+# layout below has been stable across this tag; re-validate the paths if the
+# ref is bumped.
+pinned_ref = "rails.5.0.0"
+
+[[entry]]
+path = "app/controllers/users_controller.rb"
+cap = "auth"
+vuln = true
+note = "update looks up the account with User.where(\"id = '#{params[:user][:id]}'\") and mass-assigns user_params (params.require(:user).permit!) with no ownership check — broken access control / mass-assignment privilege escalation (OWASP A4/A5)."
+
+[[entry]]
+path = "app/controllers/messages_controller.rb"
+cap = "auth"
+vuln = true
+note = "show / destroy fetch Message.where(id: params[:id]) with no check that the message belongs to current_user — insecure direct object reference (OWASP A4 broken access control)."
+
+[[entry]]
+path = "app/controllers/admin_controller.rb"
+cap = "auth"
+vuln = true
+note = "administrative actions are gated by a bypassable admin_param check (params[:admin_id] != \"1\"); update_user / delete_user act on any admin_id — broken access control / privilege escalation (OWASP A5)."
+
+[[entry]]
+path = "app/models/user.rb"
+cap = "crypto"
+vuln = true
+note = "passwords are hashed with Digest::MD5.hexdigest (hash_password / authenticate) — unsalted weak hash for credential storage (OWASP A2 cryptographic failure)."
+
+[[entry]]
+path = "app/controllers/password_resets_controller.rb"
+cap = "crypto"
+vuln = true
+note = "generate_token derives the reset token as Digest::MD5.hexdigest(email) — a predictable, forgeable password-reset token (weak cryptography)."
+
+[[entry]]
+path = "app/controllers/password_resets_controller.rb"
+cap = "deserialize"
+vuln = true
+note = "reset_password runs Marshal.load(Base64.decode64(params[:user])) on attacker-controlled input — insecure deserialization leading to RCE (OWASP A8)."
+
+[[entry]]
+path = "app/controllers/sessions_controller.rb"
+cap = "redirect"
+vuln = true
+note = "create redirects to params[:url] with no allow-list (path = params[:url] then redirect_to path) — open redirect (OWASP unvalidated redirects)."
+
+[[entry]]
+path = "app/controllers/benefit_forms_controller.rb"
+cap = "path_traversal"
+vuln = true
+note = "download builds send_file from a user-controlled params[:name] path with no containment — arbitrary file read / path traversal."
+
+[[entry]]
+path = "app/controllers/benefit_forms_controller.rb"
+cap = "deserialize"
+vuln = true
+note = "download calls params[:type].constantize.new(path), constantizing a user-supplied class name — unsafe reflection / object injection."
diff --git a/tests/eval_corpus/ground_truth/rustsec.json b/tests/eval_corpus/ground_truth/rustsec.json
new file mode 100644
index 00000000..fe51488c
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/rustsec.json
@@ -0,0 +1 @@
+[]
diff --git a/tests/eval_corpus/ground_truth/rustsec.manifest.toml b/tests/eval_corpus/ground_truth/rustsec.manifest.toml
new file mode 100644
index 00000000..8b429dc2
--- /dev/null
+++ b/tests/eval_corpus/ground_truth/rustsec.manifest.toml
@@ -0,0 +1,37 @@
+# RustSec advisory-db — Rust negative-control corpus (Phase 29, Track R.2).
+#
+# The plan's Rust real-corpus row is the RustSec advisory database.  Unlike
+# RailsGoat / DVWA / DVPWA / gosec, advisory-db ships advisory METADATA
+# (TOML + Markdown under crates/<crate>/RUSTSEC-*.md), not vulnerable Rust
+# SOURCE.  A static scan of it therefore contains zero `.rs` files and nyx
+# correctly produces zero findings — so there are no source-level vuln
+# positives to label, and no canonical scannable "RustGoat" exists to
+# substitute without fabricating paths (which the CI byte-equality + path
+# existence guards would reject outright).
+#
+# advisory-db is still worth pinning and scanning as a NEGATIVE CONTROL for
+# the Rust language path:
+#   * it exercises the Rust scan + verify pipeline (Phase 23 Rust build
+#     pool) end to end on a large real-world tree (thousands of files) and
+#     asserts it stays within the wall-clock budget without crashing, and
+#   * it is an over-confirmation guard: nyx must Confirm NOTHING on a corpus
+#     with no real source vulns.  Any Confirmed finding here is provably a
+#     false confirm and trips the per-cell false_confirmed_rate budget
+#     (tests/eval_corpus/budget.toml) — a genuine regression sentinel if a
+#     future change makes nyx treat advisory text as scannable code.
+#
+# `negative_control = true` tells manifest_gt_convert.py to emit an empty
+# `[]` ground truth.  It is mutually exclusive with `[[entry]]` tables, so a
+# real Rust vuln can never be silently hidden behind the flag.  When a
+# scannable advisory-backed Rust corpus (a vulnerable crate pinned at its
+# affected version with a source-level taint sink) is curated, drop the flag
+# and add [[entry]] tables here exactly as the other Track R.2 manifests do.
+
+corpus = "rustsec"
+upstream = "https://github.com/rustsec/advisory-db"
+# advisory-db publishes no release tags; the eval job pins the default
+# branch via the CI cache key (clone HEAD
+# eaf48e749baa3d5e27d304107d8abf175fd756bb).
+pinned_ref = "main"
+
+negative_control = true
diff --git a/tests/eval_corpus/manifest_gt_convert.py b/tests/eval_corpus/manifest_gt_convert.py
index 792338ad..0ddfefe6 100755
--- a/tests/eval_corpus/manifest_gt_convert.py
+++ b/tests/eval_corpus/manifest_gt_convert.py
@@ -23,6 +23,19 @@ Manifest schema (TOML)::
     vuln = true                             # true = real vuln, false = benign control
     note = "eval() of user-supplied pre/after-tax fields (NodeGoat A1)"
 
+Negative-control corpora.  A few real corpora carry **no** scannable
+source-level vulnerabilities of their own — most notably the RustSec
+`advisory-db`, which ships advisory *metadata* (TOML/Markdown), not
+vulnerable `.rs` source.  Such a corpus has zero ground-truth positives by
+construction, yet it is still worth scanning: it exercises the language's
+scan + verify path end to end on a large real-world tree and acts as an
+over-confirmation guard (nyx must Confirm nothing on a corpus with no real
+source vulns).  Declare it with a top-level ``negative_control = true`` and
+**zero** ``[[entry]]`` tables; the converter then emits an empty ``[]``
+ground truth.  ``negative_control`` and ``[[entry]]`` are mutually
+exclusive — a manifest that sets the flag *and* lists entries is rejected,
+so a real vuln can never be silently dropped behind the flag.
+
 Output (consumed by tabulate.py): a list of `{path, line, cap, vuln}`
 records, sorted by `(path, cap)` for deterministic, diff-stable JSON.
 `note` is intentionally dropped — the ground-truth JSON keeps the exact
@@ -119,7 +132,15 @@ def main() -> int:
 
     manifest = load_manifest(Path(args.manifest).expanduser())
     entries = manifest.get("entry", []) or []
-    if not entries:
+    negative_control = bool(manifest.get("negative_control", False))
+    if negative_control and entries:
+        print(
+            f"error: negative_control manifest must declare zero [[entry]] "
+            f"tables (found {len(entries)}): {args.manifest}",
+            file=sys.stderr,
+        )
+        return 1
+    if not entries and not negative_control:
         print(f"error: manifest has no [[entry]] tables: {args.manifest}", file=sys.stderr)
         return 1
 
@@ -184,6 +205,8 @@ def main() -> int:
 
     vuln_count = sum(1 for r in records if r["vuln"])
     print(f"wrote {len(records)} records to {out}")
+    if negative_control:
+        print("  negative-control corpus: zero ground-truth positives by construction")
     print(f"  vulns:    {vuln_count}")
     print(f"  non-vuln: {len(records) - vuln_count}")
     if corpus is not None:
diff --git a/tests/eval_corpus/run.sh b/tests/eval_corpus/run.sh
index 5ff19001..e0dd40fe 100755
--- a/tests/eval_corpus/run.sh
+++ b/tests/eval_corpus/run.sh
@@ -28,7 +28,7 @@ REPO_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
 OUTPUT_DIR=""
 NYX_BIN="${NYX_BIN:-${REPO_ROOT}/target/release/nyx}"
 CORPUS_CACHE="${NYX_EVAL_CORPUS_DIR:-${HOME}/.cache/nyx/eval_corpus}"
-SETS="owasp,sard,nodegoat,juiceshop,inhouse"
+SETS="owasp,sard,nodegoat,juiceshop,railsgoat,dvwa,dvpwa,gosec,rustsec,inhouse"
 # Optional per-cell budgets and monotonic-improvement diff.
 BUDGET_FILE=""
 DIFF_FILE=""
@@ -90,6 +90,42 @@ run_jsts_corpus() {
     || info "  tabulate.py failed on $label; ground truth file may be absent"
 }
 
+# Scan one Track R.2 polyglot real corpus and tabulate it against its
+# committed ground truth, SCOPED to its target language (tabulate --lang) so
+# incidental other-language assets (e.g. vendored JS in a Rails / aiohttp app)
+# do not pollute the corpus's per-cap metrics.  Self-skips when the corpus has
+# not been cloned into the cache; prints the exact clone command if so.
+#   $1 label  $2 dir  $3 ground-truth json  $4 target lang  $5 repo  $6 ref
+run_polyglot_corpus() {
+  local label="$1" dir="$2" gt="$3" lang="$4" repo="$5" ref="$6"
+  if [[ ! -d "$dir" ]]; then
+    info "Bootstrapping $label..."
+    info "  git clone --depth 1 --branch ${ref} ${repo} ${dir}"
+    info "Skipping $label set (not yet downloaded)."
+    return 0
+  fi
+  info "Running nyx scan on $label (lang scope: ${lang})..."
+  set +e
+  "$NYX_BIN" scan --format json --verify --no-index "$dir" \
+    > "/tmp/nyx_${label}.json" 2>"/tmp/nyx_${label}.stderr"
+  local rc=$?
+  set -e
+  if [[ $rc -ne 0 && $rc -ne 1 ]]; then
+    info "  nyx exited $rc on $label set (stderr follows):"
+    cat "/tmp/nyx_${label}.stderr" >&2
+    return 0
+  fi
+  python3 "${SCRIPT_DIR}/tabulate.py" \
+    --label "$label" \
+    --scan "/tmp/nyx_${label}.json" \
+    --ground-truth "$gt" \
+    --lang "$lang" \
+    --append "$RESULTS_JSON" \
+    ${BUDGET_FILE:+--budget "$BUDGET_FILE"} \
+    ${DIFF_FILE:+--diff "$DIFF_FILE"} \
+    || info "  tabulate.py failed on $label; ground truth file may be absent"
+}
+
 [[ -x "$NYX_BIN" ]] || die "nyx binary not found or not executable: $NYX_BIN"
 
 mkdir -p "$CORPUS_CACHE"
@@ -143,6 +179,35 @@ if [[ "$SETS" == *juiceshop* ]]; then
     "${SCRIPT_DIR}/ground_truth/juiceshop.json"
 fi
 
+# ── Polyglot real corpora (Ruby/PHP/Python/Go/Rust) — Track R.2 ───────────────
+if [[ "$SETS" == *railsgoat* ]]; then
+  run_polyglot_corpus railsgoat "${CORPUS_CACHE}/railsgoat" \
+    "${SCRIPT_DIR}/ground_truth/railsgoat.json" ruby \
+    https://github.com/OWASP/railsgoat rails.5.0.0
+fi
+if [[ "$SETS" == *dvwa* ]]; then
+  run_polyglot_corpus dvwa "${CORPUS_CACHE}/dvwa" \
+    "${SCRIPT_DIR}/ground_truth/dvwa.json" php \
+    https://github.com/digininja/DVWA 2.5
+fi
+if [[ "$SETS" == *dvpwa* ]]; then
+  run_polyglot_corpus dvpwa "${CORPUS_CACHE}/dvpwa" \
+    "${SCRIPT_DIR}/ground_truth/dvpwa.json" python \
+    https://github.com/anxolerd/dvpwa master
+fi
+if [[ "$SETS" == *gosec* ]]; then
+  run_polyglot_corpus gosec "${CORPUS_CACHE}/gosec" \
+    "${SCRIPT_DIR}/ground_truth/gosec.json" go \
+    https://github.com/securego/gosec v2.26.1
+fi
+# RustSec advisory-db is the Rust negative control (empty ground truth): the
+# row asserts the Rust scan/verify path runs and Confirms nothing there.
+if [[ "$SETS" == *rustsec* ]]; then
+  run_polyglot_corpus rustsec "${CORPUS_CACHE}/rustsec" \
+    "${SCRIPT_DIR}/ground_truth/rustsec.json" rust \
+    https://github.com/rustsec/advisory-db main
+fi
+
 # ── NIST SARD subset bootstrap ────────────────────────────────────────────────
 SARD_DIR="${CORPUS_CACHE}/nist_sard"
 if [[ "$SETS" == *sard* ]]; then
diff --git a/tests/eval_corpus/run_full.sh b/tests/eval_corpus/run_full.sh
index 948d1642..ecd142e7 100755
--- a/tests/eval_corpus/run_full.sh
+++ b/tests/eval_corpus/run_full.sh
@@ -3,6 +3,7 @@
 #
 # Drives a complete pass against every corpus set the project knows about
 # (OWASP Benchmark v1.2, the NIST SARD subset, OWASP NodeGoat + Juice Shop,
+# the Track R.2 polyglot corpora — RailsGoat / DVWA / DVPWA / gosec / RustSec —
 # and the Nyx benchmark fixtures), then emits `tests/eval_corpus/results.json`
 # for reports, diffs, and docs.
 #
@@ -70,7 +71,7 @@ set +e
 NYX_EVAL_CORPUS_DIR="$CORPUS_CACHE" \
   bash "${SCRIPT_DIR}/run.sh" \
     --nyx     "$NYX_BIN" \
-    --sets    owasp,sard,nodegoat,juiceshop,inhouse \
+    --sets    owasp,sard,nodegoat,juiceshop,railsgoat,dvwa,dvpwa,gosec,rustsec,inhouse \
     --output  "$OUTPUT_DIR" \
     --budget  "$BUDGET_FILE" \
     ${DIFF_FILE:+--diff "$DIFF_FILE"}
diff --git a/tests/eval_corpus/tabulate.py b/tests/eval_corpus/tabulate.py
index 09b19621..e537dc9f 100644
--- a/tests/eval_corpus/tabulate.py
+++ b/tests/eval_corpus/tabulate.py
@@ -362,15 +362,34 @@ def main() -> int:
         default="",
         help="path to budget.toml (per-(cap,lang) thresholds)",
     )
+    p.add_argument(
+        "--lang",
+        default="",
+        help=(
+            "comma-separated language allowlist (python, javascript, php, "
+            "ruby, go, rust, ...).  When set, only findings AND ground-truth "
+            "entries whose source language is in the list are tabulated; "
+            "everything else is dropped before tallying.  Used by the Phase 29 "
+            "polyglot corpora (Track R.2) to scope a single-language corpus to "
+            "its target language so incidental third-party assets in other "
+            "languages — e.g. the vendored JavaScript a Rails or aiohttp app "
+            "bundles — do not pollute that corpus's per-cap metrics.  Empty = "
+            "no language filter (every finding tabulated, the OWASP/JSTS "
+            "default)."
+        ),
+    )
     p.add_argument(
         "--diff",
         default="",
         help="path to a previous results JSON; fail on monotonic-improvement regression",
     )
     args = p.parse_args()
+    lang_filter = {l.strip() for l in args.lang.split(",") if l.strip()}
 
     scan_data = load_json(args.scan)
     findings = scan_data if isinstance(scan_data, list) else scan_data.get("findings", [])
+    if lang_filter:
+        findings = [f for f in findings if lang_of(f) in lang_filter]
 
     # ── Manual-triage stamping (Phase 31 follow-up) ───────────────────────
     # Cross-reference Confirmed rows against a manual-triage file before
@@ -463,6 +482,10 @@ def main() -> int:
         # Ground truth format: list of {"path": ..., "line": ..., "cap": ..., "vuln": bool}
         gt_true: list[dict] = []
         for entry in gt if isinstance(gt, list) else []:
+            # Honour the same language scope as the findings filter so recall
+            # is measured only over the corpus's target language.
+            if lang_filter and lang_of(entry) not in lang_filter:
+                continue
             if entry.get("vuln"):
                 gt_true.append({
                     "path": entry.get("path", ""),
diff --git a/tests/eval_corpus/test_manifest_gt_convert.py b/tests/eval_corpus/test_manifest_gt_convert.py
index 729adde2..f7826022 100644
--- a/tests/eval_corpus/test_manifest_gt_convert.py
+++ b/tests/eval_corpus/test_manifest_gt_convert.py
@@ -168,7 +168,16 @@ def test_committed_gt_matches_manifest(tmp: Path) -> None:
     # Offline half of the CI in-sync guard: the committed ground-truth JSON
     # must be exactly what a fresh conversion of its manifest produces.  This
     # catches a manifest edit that was not followed by a regenerate.
-    for name in ("nodegoat", "juiceshop"):
+    for name in (
+        "nodegoat",
+        "juiceshop",
+        # Track R.2 polyglot corpora (Phase 29).
+        "railsgoat",
+        "dvwa",
+        "dvpwa",
+        "gosec",
+        "rustsec",
+    ):
         man = GT_DIR / f"{name}.manifest.toml"
         committed = GT_DIR / f"{name}.json"
         assert man.exists(), f"missing manifest: {man}"
@@ -181,6 +190,39 @@ def test_committed_gt_matches_manifest(tmp: Path) -> None:
         )
 
 
+def test_negative_control_emits_empty(tmp: Path) -> None:
+    # A negative-control manifest (no scannable source vulns, e.g. RustSec
+    # advisory-db) declares `negative_control = true` and zero [[entry]]
+    # tables; the converter emits an empty `[]` ground truth.
+    man = tmp / "neg.manifest.toml"
+    man.write_text(
+        'corpus = "rustsec"\n'
+        'upstream = "https://example.test/advisory-db"\n'
+        'pinned_ref = "main"\n'
+        "negative_control = true\n"
+    )
+    out = tmp / "neg.json"
+    proc = run_convert("--manifest", str(man), "--output", str(out))
+    assert proc.returncode == 0, proc.stdout + proc.stderr
+    assert json.loads(out.read_text()) == [], out.read_text()
+    assert "negative-control corpus" in proc.stdout, proc.stdout
+
+
+def test_negative_control_with_entries_rejected(tmp: Path) -> None:
+    # negative_control and [[entry]] are mutually exclusive: a manifest that
+    # sets the flag yet lists a vuln must be rejected so a real positive can
+    # never be silently hidden behind the flag.
+    man = tmp / "neg_bad.manifest.toml"
+    man.write_text(
+        "negative_control = true\n"
+        '[[entry]]\npath = "a.rs"\ncap = "cmdi"\nvuln = true\n'
+    )
+    out = tmp / "neg_bad.json"
+    proc = run_convert("--manifest", str(man), "--output", str(out))
+    assert proc.returncode == 1, proc.stdout + proc.stderr
+    assert "negative_control" in proc.stderr and "zero" in proc.stderr, proc.stderr
+
+
 def main() -> int:
     with tempfile.TemporaryDirectory() as td:
         tmp = Path(td)
@@ -193,6 +235,8 @@ def main() -> int:
             test_malformed_manifest_exits_1,
             test_empty_manifest_exits_1,
             test_committed_gt_matches_manifest,
+            test_negative_control_emits_empty,
+            test_negative_control_with_entries_rejected,
         ):
             sub = tmp / fn.__name__
             sub.mkdir()
diff --git a/tests/eval_corpus/test_tabulate_regression.py b/tests/eval_corpus/test_tabulate_regression.py
index 8bba6758..7398b978 100644
--- a/tests/eval_corpus/test_tabulate_regression.py
+++ b/tests/eval_corpus/test_tabulate_regression.py
@@ -294,6 +294,65 @@ def test_manual_triage_ignores_vuln_true_entries(tmp: Path) -> None:
     )
 
 
+def test_lang_filter_scopes_findings_and_gt(tmp: Path) -> None:
+    # Phase 29 (Track R.2): --lang scopes a single-language corpus to its
+    # target language so incidental other-language assets (e.g. the vendored
+    # JavaScript a Rails app bundles, which nyx flags as prototype_pollution)
+    # do not pollute the corpus's per-cap metrics.  The filter must drop both
+    # findings AND ground-truth entries outside the scope.
+    gt = tmp / "gt.json"
+    write_json(
+        gt,
+        [
+            {"path": "app/models/user.rb", "line": 0, "cap": "sqli", "vuln": True},
+            {"path": "app/assets/lib.js", "line": 0, "cap": "sqli", "vuln": True},
+        ],
+    )
+    scan = tmp / "scan.json"
+    write_json(
+        scan,
+        {
+            "findings": [
+                python_finding(SINK_BIT_SQL, "/x/app/models/user.rb", 10, "NotConfirmed"),
+                # A vendored-JS finding nyx would otherwise Confirm — must be
+                # excluded entirely under `--lang ruby`.
+                python_finding(SINK_BIT_SQL, "/x/app/assets/lib.js", 10, "Confirmed"),
+            ]
+        },
+    )
+
+    # Unscoped: both language cells appear.
+    unscoped = tmp / "unscoped.json"
+    write_json(unscoped, [])
+    proc = run_tabulate(
+        "--label", "railsgoat",
+        "--scan", str(scan),
+        "--ground-truth", str(gt),
+        "--append", str(unscoped),
+    )
+    assert proc.returncode == 0, proc.stdout + proc.stderr
+    cells = {(c["cap"], c["lang"]) for c in json.loads(unscoped.read_text())[-1]["cells"]}
+    assert ("sqli", "ruby") in cells and ("sqli", "javascript") in cells, cells
+
+    # Scoped to ruby: the JS finding AND the JS ground-truth positive vanish.
+    scoped = tmp / "scoped.json"
+    write_json(scoped, [])
+    proc = run_tabulate(
+        "--label", "railsgoat",
+        "--scan", str(scan),
+        "--ground-truth", str(gt),
+        "--lang", "ruby",
+        "--append", str(scoped),
+    )
+    assert proc.returncode == 0, proc.stdout + proc.stderr
+    cells = {(c["cap"], c["lang"]): c for c in json.loads(scoped.read_text())[-1]["cells"]}
+    assert ("sqli", "javascript") not in cells, f"JS must be filtered out: {list(cells)}"
+    ruby = cells[("sqli", "ruby")]
+    assert ruby["tp"] == 1 and ruby["fn"] == 0, ruby
+    # The dropped JS positive must NOT resurface as a phantom FN in any cell.
+    assert all(lang != "javascript" for _cap, lang in cells), cells
+
+
 def test_budget_malformed_exits_3(tmp: Path) -> None:
     bad = tmp / "bad.toml"
     bad.write_text("[default]\nunsupported_rate = not_a_number\n")
@@ -601,6 +660,7 @@ def main() -> int:
             test_diff_passes_on_improvement,
             test_manual_triage_stamps_wrong_confirmed,
             test_manual_triage_ignores_vuln_true_entries,
+            test_lang_filter_scopes_findings_and_gt,
             test_budget_malformed_exits_3,
             test_relative_gt_path_suffix_matches_absolute_finding,
             test_unmatched_gt_positive_lands_in_lang_cell,