Summary
CVE-2026-82281 is a broken access control vulnerability in Kotaemon, the open-source RAG-based document chat application maintained by Cinnamon. The application fails to validate conversation ownership before performing conversation operations, allowing an attacker to view, rename, delete, or change the visibility of chat conversations belonging to other users. The issue is rated CRITICAL (CVSS v4.0 base score 9.1).
Technical details
- Root cause: the
select_conv,delete_conv,rename_conv, andon_set_public_conversationfunctions incontrol.pydo not verify that the authenticated user actually owns the conversation identifier they supply. - Trigger condition: an attacker who can reach the application supplies or guesses a conversation ID belonging to another user and invokes one of the affected functions.
- Attack vector: network-reachable, no user interaction required; classified under CWE-639 (Authorization Bypass Through User-Controlled Key).
- Impact: unauthorized read access to other users’ chat histories, and unauthorized ability to rename, delete, or toggle the public/private status of other users’ conversations — a confidentiality and integrity compromise with no direct availability impact.
Affected software
- Kotaemon (Cinnamon), versions 0 through 0.12.0 (inclusive)
Severity
- CVSS v4.0: 9.1 (Critical) —
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N - CVSS v3.1: 7.4 (High) —
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Mitigation and recommended actions
- Immediate: Upgrade Kotaemon beyond version 0.12.0 once a fixed release incorporating ownership checks for conversation management functions is available; monitor the vendor’s GitHub repository for the patched release.
- If no patch is available: Restrict network exposure of Kotaemon instances (place behind authentication proxies/VPN, avoid public internet exposure), and audit conversation management endpoints for unauthorized access attempts using unexpected conversation IDs.

