GHSA-7grx-3xcx-2xv5

### Summary The `/api/v1/files/images/{flow_id}/{file_name}` endpoint serves image files without any authentication or ownership check. Any unauthenticated request with a known flow_id and file_name returns the image with HTTP 200. ### Details `src/backend/base/langflow/api/v1/files.py:138-164` — `download_image` takes `flow_id`: UUID as a bare path parameter with no Depends(get_flow) or `CurrentActiveUser`. All other file routes (`download_file`, `upload_file`, `list_files`, `delete_file`) use `Depends(get_flow)` which enforces both authentication and ownership. There is no global auth middleware on /api/v1; protection is per-endpoint only. ### PoC ``` curl -v "http://localhost:7860/api/v1/files/images/<flow_uuid>/<filename.png>" # Returns HTTP 200 with image bytes, no auth header required ``` ### Impact Unauthenticated cross-tenant data leak. In a multi-tenant deployment, any attacker who can discover or guess a `flow_id` (UUIDs can be leaked through other API responses) can download any user's uploaded images without credentials.