CVE-2026-54029 LibreChat: IDOR in Message Deletion — Incomplete Fix for CVE-2024-41703 Leaves deleteMessages() Without User Filter

Medium 5.3 Published 25 Jun 2026 Updated 26 Jun 2026

An authenticated attacker can permanently delete other users' messages by exploiting an incomplete authorization check in the message deletion endpoint.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-54029?

CVE-2026-54029 is a medium-severity missing authorization vulnerability in Librechat Librechat, published on 25 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.4-rc1, the DELETE /api/messages/:conversationId/:messageId endpoint allows any authenticated user to delete any other user's messages. The validateMessageReq middleware only validates that the conversationId belongs to the requesting user, but the handler calls deleteMessages({ messageId }) using only the messageId as the MongoDB filter — without adding a user constraint. An attacker provides their own valid conversationId (to pass validation) and the victim's messageId (to target deletion), resulting in permanent, irrecoverable message deletion. This vulnerability is fixed in 0.8.4-rc1.

Weakness: CWE-862

Which versions are affected by CVE-2026-54029?

It affects 1 product.

Products include Librechat Librechat.

How do I fix CVE-2026-54029?

No fix has been published for CVE-2026-54029 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-54029 being exploited?

There is no known exploitation of CVE-2026-54029 in the wild and no public exploit code.

All Librechat Librechat vulnerabilities

Sources

Also known as GHSA-8892-xj8q-59xc.