SSRF in Danny-Avila Librechat
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 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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (20.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Danny-Avila Librechat — versions < 0.8.3
- Librechat — versions 0.8.3
Weakness classification (CWE)
References
- github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-31943?
- CVE-2026-31943 is a high-severity vulnerability in Danny-Avila Librechat, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.5/10. Published 2026-03-27.
- How severe is CVE-2026-31943?
- High severity. CVSS v3 base score is 8.5 out of 10.