CVE-2026-86867

Name of the Vulnerable Software and Affected Versions Kotaemon versions prior to 0.12.1

Description The multi-user chat interface contains improper access controls and incorrect authorization. Four handler methods in libs/ktem/ktem/pages/chat/control.py load conversation records using only the Conversation.id without verifying if the requester's user id matches the conversation owner. This allows an authenticated user to enumerate or guess conversation IDs to read chat transcripts, RAG (Retrieval-Augmented Generation) retrieval history, AI-generated plots, and chat suggestions, as well as permanently delete, rename, or overwrite the chat suggestion list of other users. The affected handlers are select conv(), delete conv(), rename conv(), and persist chat suggestions().

Recommendations Update to version 0.12.1 or later. As a temporary workaround, implement a reverse proxy or WAF rule to block requests to the select conv(), delete conv(), rename conv(), and persist chat suggestions() endpoints that do not include a valid user id parameter matching the authenticated session.