CVE-2026-109284

Name of the Vulnerable Software and Affected Versions Open WebUI versions 0.11.0 through 0.11.3

Description An improper authorization issue exists in the chat fork handler. The system places forked chats into the source chat's folder without verifying if the user has write access to that folder. This allows members of a shared folder whose permissions were downgraded to read-only to use the 'POST /api/v1/chats/{id}/fork' endpoint on chats they previously created. By doing so, they can insert attacker-controlled chats that are visible to the folder owner and other members.

Recommendations Update Open WebUI to version 0.11.4 or later.