CVE-2026-31943
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 8.5 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
- EPSS
- 0.21% probability · 12th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Affected
- librechat/librechat
- Source
- security-advisories@github.com
References
- https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4cExploit, Vendor Advisory
- https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4cExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.