CVE-2026-31943 — LibreChat has SSRF protection bypass via IPv4-mapped IPv6 normalization in isPrivateIP
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…
Published: 2026-03-27 · CVSS: 8.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7