CVE-2026-31945: LibreChat Server-Side Request Forgery using DNS resolution
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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-31945?
CVE-2026-31945 is classified as a critical vulnerability due to its potential for server-side request forgery (SSRF).
How do I fix CVE-2026-31945?
To fix CVE-2026-31945, upgrade LibreChat to version 0.8.2-rc3 or later, which addresses the SSRF issue.
What versions are affected by CVE-2026-31945?
CVE-2026-31945 affects LibreChat versions from 0.8.2-rc2 to 0.8.2.
What type of vulnerability is CVE-2026-31945?
CVE-2026-31945 is a server-side request forgery (SSRF) vulnerability.
Can CVE-2026-31945 lead to data exposure?
Yes, exploiting CVE-2026-31945 can lead to unauthorized access to internal services, potentially exposing sensitive data.