CVE-2026-31943

high

Description

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.

References

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c

Details

Source: Mitre, NVD

Published: 2026-03-27

Updated: 2026-03-31

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:P/A:N

Severity: High

CVSS v3

Base Score: 8.5

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Severity: High

EPSS

EPSS: 0.00028