Vulnerability · Published Sep 23, 2026 · Assigned by certcc
CVE-2026-86867Cinnamon's kotaemon contains improper authorization checks in multi‑user chat handlers
Medium 6.5
In plain English
A medium-severity missing authorization in Kotaemon from Cinnamon AI. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities).
Official description
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 `user_id` 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 products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cinnamon AI | Kotaemon | 0.12.0 |
Weakness: CWE-862, CWE-639, CWE-200 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N