# CVE-2026-31943: LibreChat is a ChatGPT clone with additional features. Prior to version 0.8.3, `isPrivateIP()` in…

Source: https://junglewise.ai/threats/cve-2026-31943-librechat-is-a-chatgpt-clone-with-additional-features-prior-to  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-27  
License: CC BY 4.0 with a link back

CVE-2026-31943 · Severity: high · CVSS 8.5 · Published 2026-03-27

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.

Technologies: [LibreChat](https://junglewise.ai/threats/technologies/librechat). Vendors: [LibreChat](https://junglewise.ai/threats/vendors/librechat).

## Quick answers

**Is CVE-2026-31943 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-31943 being exploited in the wild.

**How severe is CVE-2026-31943?** High severity, with a CVSS score of 8.5, published 27 March 2026.

**Which products and versions are affected?** LibreChat. The advisory does not name versions.

**Is there a fix for CVE-2026-31943?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2026-31943?** Check whether you run LibreChat. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- LibreChat

## Related threats

- [LibreChat 2FA bypass via unauthenticated backup code regeneration](https://junglewise.ai/threats/cve-2026-54040-librechat-2fa-bypass-via-unauthenticated-backup-code-regeneration)
- [LibreChat resource exhaustion via missing rate limiting in duplicate endpoint](https://junglewise.ai/threats/cve-2026-54037-librechat-resource-exhaustion-via-missing-rate-limiting-in)
- [LibreChat SSRF via custom endpoint baseURL](https://junglewise.ai/threats/cve-2026-54033-librechat-ssrf-via-custom-endpoint-baseurl)
- [LibreChat token theft via missing OAuth resource validation in MCP](https://junglewise.ai/threats/cve-2026-54030-librechat-token-theft-via-missing-oauth-resource-validation-in)
- [danny-avila LibreChat IDOR in message deletion endpoint](https://junglewise.ai/threats/cve-2026-54029-danny-avila-librechat-idor-in-message-deletion-endpoint)