Open WebUI has Broken Access Control for Completions API

Summary Any user X can continue the conversation of any other user Y, as long as the Chat ID of Y is known. User X does not even need to be an admin to do so. Details A user just needs to use the API endpoint: /api/chat/completions with their own API key generated in OWUI and the Chat ID of anoth...

PT-2026-41179

Name of the Vulnerable Software and Affected Versions Open WebUI versions prior to 0.9.0 Description An issue exists where a user can continue the conversation of another user if the target user's Chat ID is known. This occurs because the system fails to verify if the Chat ID matches the user who...