CVE-2026-31943

HIGH

8.5

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.

CVE Details

CVSS v3.1 Score8.5

SeverityHIGH

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

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredLOW

User InteractionNONE

Published3/27/2026

Last Modified3/31/2026

Sourcenvd

Honeypot Sightings0

Affected Products

librechat:librechat

Weaknesses (CWE)

CWE-918

References

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

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c(134c704f-9b21-4f2e-91b3-4a467353bcc0)

IOC Correlations

No correlations recorded

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