diff --git a/cmd/soc/main.go b/cmd/soc/main.go
index ee6069d..b2cc44c 100644
--- a/cmd/soc/main.go
+++ b/cmd/soc/main.go
@@ -19,6 +19,7 @@ import (
 	"runtime"
 	"runtime/debug"
 	"strconv"
+	"strings"
 	"syscall"
 
 	"github.com/syntrex/gomcp/internal/application/soc"
@@ -122,6 +123,16 @@ func main() {
 	socSvc := soc.NewService(socRepo, decisionLogger)
 	srv := sochttp.New(socSvc, port)
 
+	// Configure CORS
+	if corsEnv := env("SOC_CORS_ORIGIN", ""); corsEnv != "" {
+		parts := strings.Split(corsEnv, ",")
+		for i := range parts {
+			parts[i] = strings.TrimSpace(parts[i])
+		}
+		srv.SetCORSOrigins(parts)
+		slog.Info("CORS strict origins configured", "origins", len(parts))
+	}
+
 	// Threat Intelligence Store — always initialized for IOC enrichment (§6)
 	threatIntelStore := soc.NewThreatIntelStore()
 	threatIntelStore.AddDefaultFeeds()
diff --git a/internal/transport/http/middleware.go b/internal/transport/http/middleware.go
index cf52256..29ddeca 100644
--- a/internal/transport/http/middleware.go
+++ b/internal/transport/http/middleware.go
@@ -2,57 +2,48 @@ package httpserver
 
 import (
 	"net/http"
-	"os"
-	"strings"
 )
 
-// corsAllowedOrigins returns the configured CORS origins.
-// Set SOC_CORS_ORIGIN in production (e.g. "https://syntrex.pro,https://xn--80akacl3adqr.xn--p1acf").
-// Defaults to "*" for local development.
-func corsAllowedOrigins() []string {
-	if v := os.Getenv("SOC_CORS_ORIGIN"); v != "" {
-		parts := strings.Split(v, ",")
-		for i := range parts {
-			parts[i] = strings.TrimSpace(parts[i])
-		}
-		return parts
-	}
-	return []string{"*"}
-}
-
-// corsMiddleware adds CORS headers with configurable origin.
-// Production: set SOC_CORS_ORIGIN=https://syntrex.pro,https://xn--80akacl3adqr.xn--p1acf
-func corsMiddleware(next http.Handler) http.Handler {
-	origins := corsAllowedOrigins()
-	allowAll := len(origins) == 1 && origins[0] == "*"
+// corsMiddleware adds CORS headers with strict origin validation.
+// Production: SetCORSOrigins should be called with ["https://syntrex.pro"]
+func corsMiddleware(origins []string) func(http.Handler) http.Handler {
+	allowAll := false
 	allowedSet := make(map[string]bool, len(origins))
 	for _, o := range origins {
+		if o == "*" {
+			allowAll = true
+		}
 		allowedSet[o] = true
 	}
 
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if allowAll {
-			w.Header().Set("Access-Control-Allow-Origin", "*")
-		} else {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			reqOrigin := r.Header.Get("Origin")
-			if allowedSet[reqOrigin] {
+			if reqOrigin != "" {
+				if !allowAll && !allowedSet[reqOrigin] {
+					http.Error(w, "CORS origin not allowed", http.StatusForbidden)
+					return
+				}
 				w.Header().Set("Access-Control-Allow-Origin", reqOrigin)
 				w.Header().Set("Vary", "Origin")
+			} else if allowAll {
+				w.Header().Set("Access-Control-Allow-Origin", "*")
 			}
-		}
-		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, PATCH, DELETE, OPTIONS")
-		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization, X-API-Key")
-		w.Header().Set("Access-Control-Allow-Credentials", "true")
-		w.Header().Set("Access-Control-Max-Age", "86400")
+			
+			w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, PATCH, DELETE, OPTIONS")
+			w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization, X-API-Key")
+			w.Header().Set("Access-Control-Allow-Credentials", "true")
+			w.Header().Set("Access-Control-Max-Age", "86400")
 
-		// Handle preflight
-		if r.Method == http.MethodOptions {
-			w.WriteHeader(http.StatusNoContent)
-			return
-		}
+			// Handle preflight
+			if r.Method == http.MethodOptions {
+				w.WriteHeader(http.StatusNoContent)
+				return
+			}
 
-		next.ServeHTTP(w, r)
-	})
+			next.ServeHTTP(w, r)
+		})
+	}
 }
 
 // securityHeadersMiddleware adds defense-in-depth headers to all responses.
diff --git a/internal/transport/http/server.go b/internal/transport/http/server.go
index 002a960..b8b557c 100644
--- a/internal/transport/http/server.go
+++ b/internal/transport/http/server.go
@@ -53,6 +53,7 @@ type Server struct {
 	srv              *http.Server
 	tlsCert          string
 	tlsKey           string
+	corsOrigins      []string
 }
 
 // cachedScan stores a cached scan result with expiry.
@@ -80,6 +81,14 @@ func New(socSvc *appsoc.Service, port int) *Server {
 		wsHub:       NewWSHub(),
 		scanSem:     make(chan struct{}, 6), // Max 6 concurrent scans (~2 per CPU)
 		scanCache:   make(map[string]*cachedScan, 500),
+		corsOrigins: []string{"http://localhost:3000", "https://syntrex.pro"}, // Default secure fallback
+	}
+}
+
+// SetCORSOrigins configures the allowed origins for CORS strictly.
+func (s *Server) SetCORSOrigins(origins []string) {
+	if len(origins) > 0 {
+		s.corsOrigins = origins
 	}
 }
 
@@ -378,7 +387,7 @@ func (s *Server) Start(ctx context.Context) error {
 	if s.jwtAuth != nil {
 		handler = s.jwtAuth.Middleware(handler)
 	}
-	handler = corsMiddleware(handler)
+	handler = corsMiddleware(s.corsOrigins)(handler)
 	handler = securityHeadersMiddleware(handler)
 	handler = s.rateLimiter.Middleware(handler)
 	handler = s.metrics.Middleware(handler)
diff --git a/internal/transport/http/soc_handlers_test.go b/internal/transport/http/soc_handlers_test.go
index 3ebe1d3..f1fea13 100644
--- a/internal/transport/http/soc_handlers_test.go
+++ b/internal/transport/http/soc_handlers_test.go
@@ -63,7 +63,7 @@ func newTestServer(t *testing.T) (*httptest.Server, *appsoc.Service) {
 	mux.HandleFunc("GET /api/soc/incident-explain/{id}", srv.handleIncidentExplain)
 	mux.HandleFunc("GET /health", srv.handleHealth)
 
-	ts := httptest.NewServer(corsMiddleware(mux))
+	ts := httptest.NewServer(corsMiddleware([]string{"*"})(mux))
 	t.Cleanup(ts.Close)
 
 	return ts, socSvc