CVE-2026-31943: CWE-918: Server-Side Request Forgery (SSRF) in danny-avila LibreChat
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.
AI Analysis
Technical Summary
LibreChat versions before 0.8.3 contain an SSRF vulnerability due to improper detection of IPv4-mapped IPv6 addresses by the isPrivateIP() function in the authentication domain code. This flaw allows authenticated users to circumvent SSRF protections and make the server issue HTTP requests to internal network addresses, including cloud metadata endpoints and private IP ranges. The vulnerability is tracked as CVE-2026-31943 with a high CVSS score of 8.5. The issue is resolved in LibreChat version 0.8.3.
Potential Impact
Exploitation of this vulnerability allows an authenticated user to make the LibreChat server perform HTTP requests to internal network resources that are normally inaccessible externally. This includes access to cloud metadata services (e.g., AWS 169.254.169.254), loopback interfaces, and RFC1918 private IP ranges. Such access can lead to unauthorized information disclosure, including sensitive cloud instance metadata, which may contain credentials or configuration data. The integrity impact is limited (low), and availability is not affected.
Mitigation Recommendations
A patch is available in LibreChat version 0.8.3 that fixes the SSRF vulnerability by correctly detecting IPv4-mapped IPv6 addresses. Users should upgrade to version 0.8.3 or later to remediate this issue. There is no indication that temporary mitigations or workarounds are provided by the vendor. Since this is not a cloud-hosted service, remediation depends on applying the official fix.
CVE-2026-31943: CWE-918: Server-Side Request Forgery (SSRF) in danny-avila LibreChat
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 v3.1
Score 8.5high
Affected software
pkg:github/danny-avila/LibreChatRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
LibreChat versions before 0.8.3 contain an SSRF vulnerability due to improper detection of IPv4-mapped IPv6 addresses by the isPrivateIP() function in the authentication domain code. This flaw allows authenticated users to circumvent SSRF protections and make the server issue HTTP requests to internal network addresses, including cloud metadata endpoints and private IP ranges. The vulnerability is tracked as CVE-2026-31943 with a high CVSS score of 8.5. The issue is resolved in LibreChat version 0.8.3.
Potential Impact
Exploitation of this vulnerability allows an authenticated user to make the LibreChat server perform HTTP requests to internal network resources that are normally inaccessible externally. This includes access to cloud metadata services (e.g., AWS 169.254.169.254), loopback interfaces, and RFC1918 private IP ranges. Such access can lead to unauthorized information disclosure, including sensitive cloud instance metadata, which may contain credentials or configuration data. The integrity impact is limited (low), and availability is not affected.
Mitigation Recommendations
A patch is available in LibreChat version 0.8.3 that fixes the SSRF vulnerability by correctly detecting IPv4-mapped IPv6 addresses. Users should upgrade to version 0.8.3 or later to remediate this issue. There is no indication that temporary mitigations or workarounds are provided by the vendor. Since this is not a cloud-hosted service, remediation depends on applying the official fix.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-10T15:10:10.656Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 69c6de373c064ed76fea1d62
Added to database: 03/27/2026, 19:44:55 UTC
Last enriched: 04/04/2026, 10:50:17 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 82
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