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.

CVSS v3 8.5 HIGH

8.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.1 / Impact : 4.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c	Exploit Vendor Advisory
https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:librechat:librechat::::::::
	cpe:2.3:a:librechat:librechat:0.8.3:rc1::::::
	cpe:2.3:a:librechat:librechat:0.8.3:rc2::::::

History

26 Oct 2026, 21:10

Type	Values Removed	Values Added
Summary		(es) LibreChat es un clon de ChatGPT con características adicionales. Antes de la versión 0.8.3, ’isPrivateIP()’ en ’packages/api/src/auth/domain.ts’ no detecta direcciones IPv6 mapeadas a IPv4 en su forma hexadecimal normalizada, permitiendo a cualquier usuario autenticado eludir la protección SSRF y hacer que el servidor emita solicitudes HTTP a recursos de red internos - incluyendo servicios de metadatos en la nube (p. ej., AWS ’169.254.169.254’), loopback y rangos RFC1918. La versión 0.8.3 corrige el problema.

Information

Published : 2026-03-27 20:16

Updated : 2026-10-26 21:10

NVD link : CVE-2026-31943

Mitre link : CVE-2026-31943

CVE.ORG link : CVE-2026-31943

JSON object : View

Products Affected

librechat

librechat

CWE

CWE-918

Server-Side Request Forgery (SSRF)

{"id": "CVE-2026-31943", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-31943", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-31T18:38:43.982569Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 4.7, "exploitabilityScore": 3.1}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "danny-avila", "product": "LibreChat", "versions": [{"status": "affected", "version": "< 0.8.3"}]}]}], "published": "2026-03-27T20:16:29.897", "references": [{"url": "https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-918"}]}], "descriptions": [{"lang": "en", "value": "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 \u2014 including cloud metadata services (e.g., AWS `169.254.169.254`), loopback, and RFC1918 ranges. Version 0.8.3 fixes the issue."}, {"lang": "es", "value": "LibreChat es un clon de ChatGPT con caracter\u00edsticas adicionales. Antes de la versi\u00f3n 0.8.3, \u2019isPrivateIP()\u2019 en \u2019packages/api/src/auth/domain.ts\u2019 no detecta direcciones IPv6 mapeadas a IPv4 en su forma hexadecimal normalizada, permitiendo a cualquier usuario autenticado eludir la protecci\u00f3n SSRF y hacer que el servidor emita solicitudes HTTP a recursos de red internos - incluyendo servicios de metadatos en la nube (p. ej., AWS \u2019169.254.169.254\u2019), loopback y rangos RFC1918. La versi\u00f3n 0.8.3 corrige el problema."}], "lastModified": "2026-10-26T21:10:00.170", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2D34833A-E49E-47F0-8C2E-0D55B6CF59BB", "versionEndExcluding": "0.8.3"}, {"criteria": "cpe:2.3:a:librechat:librechat:0.8.3:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "482D0FE3-2AB3-47B6-982E-564A5B824464"}, {"criteria": "cpe:2.3:a:librechat:librechat:0.8.3:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "451E27B8-D779-4C62-AF93-C8EF026E3B09"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}