CVE-2026-82284

Quivr through version 0.0.322 fails to verify that a chat belongs to the requesting user in three API endpoints (GET /chat/{chat_id}/history, DELETE /chat/{chat_id}, and POST /chat/{chat_id}/question/answer), an object-level authorization bypass known as an IDOR (CWE-639). Any authenticated attacker who guesses or supplies another user's chat_id can read that conversation's history, including content drawn from the owner's private knowledge base, delete the chat outright, or inject fabricated messages into it. The flaw is network-exploitable with low privileges and no user interaction, and the high CVSS 4.0 score (8.6) reflects the high confidentiality and integrity impact of reading and tampering with other users' chats. All Quivr deployments running version 0.0.322 or earlier with multiple authenticated users are affected; single-user self-hosted instances face little risk. There is no public proof-of-concept, the flaw is not in CISA's KEV catalog, and EPSS estimates only a 0.2% chance of exploitation in the next 30 days, so no in-the-wild exploitation is currently known.

What to do: Upgrade Quivr to the latest release (anything newer than 0.0.322) as soon as a patched version is published, and track the project's advisories for the fixed version number. Until you patch, review application logs for requests to /chat/{chat_id}/history, /chat/{chat_id}, and /chat/{chat_id}/question/answer where the chat_id belongs to a different user, and consider restricting multi-user access to the deployment or applying a custom ownership check on these endpoints. Because private knowledge base content can be exposed, treat any cross-tenant chat access found in logs as a potential data disclosure.