CVE-2026-31945 LibreChat Server-Side Request Forgery using DNS resolution

High 7.7 Published 27 Mar 2026 Updated 30 Mar 2026

Attackers can bypass hostname validation via DNS resolution to access internal resources in LibreChat agent actions or MCP features.

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-2026-31945?

CVE-2026-31945 is a high-severity server-side request forgery vulnerability in Librechat Librechat, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

LibreChat is a ChatGPT clone with additional features. Versions 0.8.2-rc2 through 0.8.2 are vulnerable to a server-side request forgery (SSRF) attack when using agent actions or MCP. Although a previous SSRF vulnerability (https://github.com/danny-avila/LibreChat/security/advisories/GHSA-rgjq-4q58-m3q8) was reported and patched, the fix only introduced hostname validation. It does not verify whether DNS resolution results in a private IP address. As a result, an attacker can still bypass the protection and gain access to internal resources, such as an internal RAG API or cloud instance metadata endpoints. Version 0.8.3-rc1 contains a patch.

Weakness: CWE-918

Which versions are affected by CVE-2026-31945?

It affects 1 product.

Products include Librechat Librechat.

How do I fix CVE-2026-31945?

No fix has been published for CVE-2026-31945 yet. Limit exposure of the affected software until one is available.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2026-31945 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31945 exists.

All Librechat Librechat vulnerabilities

Sources

Also known as GHSA-f92m-jpv7-55p2.