CVE-2026-31943

published 2026-03-27

CVE-2026-31943: 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…

Priority P3 54 high 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.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
danny-avila	librechat	< 0.8.3	0.8.3
librechat	librechat	< 0.8.3	0.8.3
librechat	librechat	—	—

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CWE-918