CVE-2026-31943— LibreChat has SSRF protection bypass via IPv4-mapped IPv6 normalization in isPrivateIP
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I. Basic Information for CVE-2026-31943
Vulnerability Information
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Vulnerability Title
LibreChat has SSRF protection bypass via IPv4-mapped IPv6 normalization in isPrivateIP
Source: NVD (National Vulnerability Database)
Vulnerability 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.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
Source: NVD (National Vulnerability Database)
Vulnerability Type
服务端请求伪造(SSRF)
Source: NVD (National Vulnerability Database)
Vulnerability Title
LibreChat 代码问题漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
LibreChat是LibreChat开源的一个免费、高度可定制的统一 AI 对话平台，能够在一个界面中聚合并运行来自任意厂商的大模型。 LibreChat 0.8.3之前版本存在代码问题漏洞，该漏洞源于packages/api/src/auth/domain.ts中的isPrivateIP函数未能检测十六进制规范化形式的IPv4映射IPv6地址，可能导致任何经过身份验证的用户绕过SSRF保护，使服务器向内部网络资源发出HTTP请求。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| danny-avila | LibreChat | < 0.8.3 | - |
II. Public POCs for CVE-2026-31943
| # | POC Description | Source Link | Shenlong Link |
|---|
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Same Patch Batch · danny-avila · 2026-03-27 · 4 CVEs total
| CVE-2026-31945 | 7.7 HIGH | LibreChat Server-Side Request Forgery using DNS resolution |
| CVE-2026-31951 | 6.8 MEDIUM | LibreChat's MCP Server Header Injection Enables OAuth Token Theft |
| CVE-2026-31950 | 5.3 MEDIUM | LibreChat's IDOR in SSE Stream Subscription Allows Reading Other Users' Chats |
IV. Related Vulnerabilities
Same product: LibreChat
- CVE-2026-34371
LibreChat Affected by Arbitrary File Write via `execute_code - CVE-2026-31951
LibreChat's MCP Server Header Injection Enables OAuth Token - CVE-2026-31950
LibreChat's IDOR in SSE Stream Subscription Allows Reading O - CVE-2026-31945
LibreChat Server-Side Request Forgery using DNS resolution - CVE-2026-33265
LibreChat 安全漏洞
Same vendor: danny-avila
- CVE-2026-34371
LibreChat Affected by Arbitrary File Write via `execute_code - CVE-2026-31951
LibreChat's MCP Server Header Injection Enables OAuth Token - CVE-2026-31950
LibreChat's IDOR in SSE Stream Subscription Allows Reading O - CVE-2026-31945
LibreChat Server-Side Request Forgery using DNS resolution - CVE-2025-41258
LibreChat RAG API Authentication Bypass
Same weakness: CWE-918
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New API: SSRF Filter Bypass via 0.0.0.0
V. Comments for CVE-2026-31943
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