diff --git a/apps/api/src/middleware/dynamic_cors.py b/apps/api/src/middleware/dynamic_cors.py
index dbc7d5a..2a40cc1 100644
--- a/apps/api/src/middleware/dynamic_cors.py
+++ b/apps/api/src/middleware/dynamic_cors.py
@@ -35,6 +35,11 @@ def _is_public_path(path: str) -> bool:
     return any(path.startswith(prefix) for prefix in PUBLIC_PATH_PREFIXES)
 
 
+def _normalize_domain(domain: str) -> str:
+    """Strip leading www. for comparison purposes."""
+    return domain.removeprefix("www.")
+
+
 def _extract_site_id_from_path(path: str) -> str | None:
     """Extract site_id UUID from public config path like /api/v1/config/sites/{id}."""
     parts = path.split("/")
@@ -49,7 +54,11 @@ def _extract_site_id_from_path(path: str) -> str | None:
 async def _get_allowed_origins_for_site(
     db: AsyncSession, site_id: str
 ) -> set[str]:
-    """Return all registered domains (primary + additional) for a site."""
+    """Return all registered domains (primary + additional) for a site.
+
+    Domains are stored without www. prefix; the origin is similarly
+    stripped before comparison so both variants match.
+    """
     try:
         site_uuid = uuid.UUID(site_id)
     except (ValueError, TypeError):
@@ -66,9 +75,9 @@ async def _get_allowed_origins_for_site(
     if not site:
         return set()
 
-    origins: set[str] = {site.domain}
+    origins: set[str] = {_normalize_domain(site.domain)}
     if site.additional_domains:
-        origins.update(site.additional_domains)
+        origins.update(_normalize_domain(d) for d in site.additional_domains)
     return origins
 
 
@@ -96,26 +105,29 @@ class DynamicCORSMedium(BaseHTTPMiddleware):
 
         site_id = _extract_site_id_from_path(request.url.path)
 
-        if site_id:
-            # Async db session required — get from request state if already set
-            # by the dependency injection, otherwise create a new one
-            db = request.state.db if hasattr(request.state, "db") else None
-            if db is None:
-                # Fall back to a new session for this lookup only
-                allowed: set[str] = set()
-                async for session in get_db():
-                    allowed = await _get_allowed_origins_for_site(session, site_id)
-                    break
-            else:
-                allowed = await _get_allowed_origins_for_site(db, site_id)
+        if not site_id:
+            return await call_next(request)
 
-            if origin in allowed:
-                response = await call_next(request)
-                response.headers["Access-Control-Allow-Origin"] = origin
-                response.headers["Access-Control-Allow-Credentials"] = "true"
-                response.headers["Access-Control-Allow-Methods"] = "*"
-                response.headers["Access-Control-Allow-Headers"] = "*"
-                return response
+        # Async db session required — get from request state if already set
+        # by the dependency injection, otherwise create a new one
+        db = request.state.db if hasattr(request.state, "db") else None
+        if db is None:
+            # Fall back to a new session for this lookup only
+            allowed: set[str] = set()
+            async for session in get_db():
+                allowed = await _get_allowed_origins_for_site(session, site_id)
+                break
+        else:
+            allowed = await _get_allowed_origins_for_site(db, site_id)
+
+        # Normalize origin (strip www.) before comparing
+        if _normalize_domain(origin) in allowed:
+            response = await call_next(request)
+            response.headers["Access-Control-Allow-Origin"] = origin
+            response.headers["Access-Control-Allow-Credentials"] = "true"
+            response.headers["Access-Control-Allow-Methods"] = "*"
+            response.headers["Access-Control-Allow-Headers"] = "*"
+            return response
 
         # Site not found or origin not registered — let the normal
         # CORS middleware/global allowed_origins handle it