LibreChat — Ssrf (CVE-2026-31943)
Date: 2026-03
Affected: librechat/librechat
Attack vector: ssrf
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-31943
CWE: CWE-918
CVSS: 8.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N)

LibreChat is a ChatGPT clone with additional features. Prior to version 0.8.3, `isPrivateIP()` in `packages/api/src/auth/domain.ts` fails to detect IPv4-mapped IPv6 addresses in their hex-normalized form, allowing any authenticated user to bypass SSRF protection and make the server issue HTTP requests to internal network resources — including cloud metadata services (e.g., AWS `169.254.169.254`), loopback, and RFC1918 ranges. Version 0.8.3 fixes the issue.


Mitigations:

Architectural layers (MAESTRO):