CVE-2026-54029

CVE-2026-54029 is a medium-severity vulnerability in Librechat with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-862.

Key facts

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.

Frequently asked questions

What is CVE-2026-54029?
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.
How severe is CVE-2026-54029?
CVE-2026-54029 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-54029 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-54029?
CVE-2026-54029 affects Librechat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-54029?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-54029 have an EU (EUVD) identifier?
Yes. CVE-2026-54029 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39461.
When was CVE-2026-54029 published?
CVE-2026-54029 was published on 2026-06-25 and last updated on 2026-06-29.

References

Affected products (1)

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