CVE-2026-54033: LibreChat: SSRF via User-Provided Custom Endpoint baseURL — no private IP validation on user-configured API base URLs

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-25 · updated 2026-10-25
Weakness: CWE-918

Description

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.4-rc1, LibreChat allows users to configure custom OpenAI-compatible API endpoints by setting a baseURL. This URL is used to construct HTTP requests without any SSRF validation — no private IP check, no scheme restriction, no DNS pinning. An authenticated user can set baseURL to internal network addresses. This vulnerability is fixed in 0.8.4-rc1.

Affected products

danny-avila LibreChat: through 0.8.3

References

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-gc9r-88c3-7qhq
https://github.com/danny-avila/LibreChat/security/advisories/GHSA-gc9r-88c3-7qhq

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