2. Image MIME type whitelist — _ALLOWED_IMAGE_TYPES blocks SVG XSS in both servers
3. Filename collision safety — _unique_image_name() helper in both servers
4. OAuth CSRF — state token generated in edit/server.py auth-url, stored in _oauth_states, validated and discarded in callback; strava_api.auth_url() accepts optional state param
5. Error message leak — upload processing errors now return generic "Processing failed" instead of exception type/message
6. Handle injection in subprocess — _trigger_rebuild now asserts handle matches _VALID_HANDLE before passing to subprocess
Davide Scaini