CVE-2026-31943

Published: Mar 27, 2026Modified: Jun 17, 2026

8.5

Vector

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

Exploitability: 3.1 / Impact: 4.7

Source: security-advisories@github.com (Secondary)

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.

Affected (3)

Products: Librechat: Librechat

1 product

Configuration A

3 vulnerable

Vulnerable Software	Affected Versions
Librechat Librechat	Before 0.8.3
Librechat Librechat	Version 0.8.3 rc1
Librechat Librechat	Version 0.8.3 rc2

Related CWEs

Server-Side Request Forgery (SSRF)

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

References (2)

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

Source: security-advisories@github.com

ExploitVendor Advisory

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

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

ExploitVendor Advisory

Timeline

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