Executive brief
Onyx is an open-source AI platform used for managing chat sessions and document uploads. A security flaw allows any logged-in user to download files uploaded by other users, including confidential documents and chat attachments, if they know the file's unique identifier. This could lead to the unauthorized exposure of sensitive corporate data or private conversations.
Technical details
An Insecure Direct Object Reference (IDOR) vulnerability exists in the GET /chat/file/{file_id} endpoint of the Onyx AI platform. While the endpoint requires authentication, it fails to perform an ownership check to ensure the requesting user is authorized to access the specific file_id provided. An attacker with a valid account can retrieve any file by supplying its UUID, as the backend logic in chat_backend.py discards the user object and fetches the file record solely based on the identifier. This issue affects versions prior to 3.0.9, 3.1.6, and 3.2.6, where patches have been implemented to enforce proper authorization.
Affected products
- Onyx Onyx AI Platform < 3.0.9, >= 3.1.0 < 3.1.6, >= 3.2.0 < 3.2.6
Timeline
- 2026-04-29: advisory: GitHub Security Advisory published
- 2026-05-08: disclosed: CVE published to NVD