CVE-2026-31943: LibreChat is a ChatGPT clone with additional features. Prior to version 0.8.3, `isPrivateIP()` in…
CVE-2026-31943 · Severity: high · CVSS 8.5 · Published 2026-03-27
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.
No. Junglewise Threat Intelligence has no report of CVE-2026-31943 being exploited in the wild.
How severe is CVE-2026-31943?
High severity, with a CVSS score of 8.5, published 27 March 2026.
Which products and versions are affected?
LibreChat. The advisory does not name versions.
Is there a fix for CVE-2026-31943?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-31943?
Check whether you run LibreChat. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.