CVE-2026-86867: Cinnamon's kotaemon contains improper authorization checks in multi‑user chat handlers
Cinnamon's Kotaemon (all versions up to and including v0.12.0) multi-user chat interface contains multiple vulnerabilities due to incorrect authorization and improper access controls. There are four handler methods in libs/ktem/ktem/pages/chat/control.py that load a Conversation record by its ID without comparing the requester's userid to the conversation's owner Conversation.user. This allows any authenticated user to perform the following actions: 1. Read other user's chat transcripts, RAG retrieval history, AI-generated plots, and chat suggestions. 2. Permanently delete another user's conversation. 3. Rename another user's conversation. 4. Overwrite another user's conversation's chat suggestion list.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue?
Any authenticated Kotaemon user can exploit it. The affected handlers do not verify that the requester owns the Conversation record identified by the supplied conversation ID.
What information and actions are exposed?
An attacker can read another user's chat transcripts, RAG retrieval history, AI-generated plots, and chat suggestions. They can also delete or rename another user's conversation, or overwrite its chat suggestion list.
Which versions are affected?
All Cinnamon Kotaemon versions up to and including v0.12.0 are affected.