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HIGH · 8.5

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 IPv6 addresses in their hex-normalized f...

Vulnerability 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.

CVSS Score

8.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE

Affected Products

VendorProductVersions
LibrechatLibrechat< 0.8.3

Related Weaknesses (CWE)

CWE-918

References

FAQ

What is CVE-2026-31943?

CVE-2026-31943 is a vulnerability with a CVSS score of 8.5 (HIGH). 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 f...

How severe is CVE-2026-31943?

CVE-2026-31943 has been rated HIGH with a CVSS base score of 8.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-31943?

Check the references section above for vendor advisories and patch information. Affected products include: Librechat Librechat.