Hermes WebUI < 0.51.443 - Cross-Profile Session Data Exfiltration via Session Export Endpoint

An authenticated attacker who knows or guesses a session identifier belonging to another Hermes profile can call `GET /api/session/export?session_id=<id>` or `GET /api/session?session_id=<id>` to retrieve that session's full transcript or metadata. The `_handle_session_export` handler in `api/routes.py` loaded the session purely by identifier without verifying that the session's `profile` attribute matches the active profile of the requesting user [ref_id=2]. Because the session list endpoint (`/api/sessions`) already scoped results to the active profile, the by-id endpoints created a direct authorization bypass [CWE-639].

The patch adds a `_profiles_match(getattr(s, 'profile', None), active_profile)` check in `_handle_session_export` and a `_session_visible_to_active_profile` guard in `handle_get` before serializing or returning any session data [patch_id=6466839]. If the session's profile does not match the active profile, the handler returns a generic `404` ("Session not found") instead of the transcript, preventing both data exfiltration and the ability to distinguish a foreign session from a nonexistent one. The same check is also applied to the CLI-session fallback path.