CVE-2026-31943

Severity CVSS v4.0:

Pending analysis

Type:

CWE-918 Server-Side Request Forgery (SSRF)

Publication date:

27/03/2026

Last modified:

31/03/2026

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 8.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): Low
Availability (A): None

Base Score 3.x

8.50

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:librechat:librechat::::::::		0.8.3 (excluding)
cpe:2.3:a:librechat:librechat:0.8.3:rc1::::::
cpe:2.3:a:librechat:librechat:0.8.3:rc2::::::

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-31943

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools