PT-2026-28429 · Librechat · Librechat

Danny-Avila · Published 2026-03-27 · Updated 2026-03-28 · CVE-2026-31943

Positive Technologies (AI Summary)

CVSS v3.1

8.5

High

Base vector

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

Name of the Vulnerable Software and Affected Versions LibreChat versions prior to 0.8.3

Description LibreChat is a ChatGPT clone with additional features. Prior to version 0.8.3, the isPrivateIP() function in packages/api/src/auth/domain.ts does not correctly identify IPv4-mapped IPv6 addresses in their hex-normalized form. This allows any authenticated user to bypass Server-Side Request Forgery (SSRF) protection. Successful exploitation enables the server to make HTTP requests to internal network resources, including cloud metadata services (e.g., AWS 169.254.169.254), loopback, and RFC1918 ranges. The vulnerable function is isPrivateIP(). The affected API endpoint is not explicitly mentioned.

Recommendations Upgrade to version 0.8.3 to resolve this issue.

Exploit

Fix

SSRF

Weakness Enumeration

CWE-918

Related Identifiers

CVE-2026-31943

GHSA-W5R7-4F94-VP4C

Affected Products

Librechat

References · 8

• 🔥 https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c · Exploit
• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31943.json · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-31943 · Security Note
• https://osv.dev/vulnerability/CVE-2026-31943 · Vendor Advisory
• https://twitter.com/CVEnew/status/2037719424149667854 · Twitter Post
• https://twitter.com/TheHackerWire/status/2037635855096144223 · Twitter Post
• https://twitter.com/TheHackerWire/status/2037650891487268917 · Twitter Post
• https://twitter.com/CveFindCom/status/2037631437428449669 · Twitter Post