LibreChat has SSRF protection bypass via IPv4-mapped IPv6 normalization in isPrivateIP
Priority HIGH 70CWE-918Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00221 12th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed LibreChat (danny-avila): 0.8.3
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| danny-avila | LibreChat | before 0.8.3 | 0.8.3 | Patch available | CNA |
- LibreChat Vendordanny-avila Affected before 0.8.3 Fixed in 0.8.3 Patch available CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:* | before 0.8.3 | Vulnerable | danny-avila |
| cpe:2.3:a:librechat:librechat:0.8.3:rc1:*:*:*:*:*:* | 0.8.3 rc1 | Vulnerable | danny-avila |
| cpe:2.3:a:librechat:librechat:0.8.3:rc2:*:*:*:*:*:* | 0.8.3 rc2 | Vulnerable | danny-avila |
- cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:* Versions before 0.8.3 Vulnerable ·danny-avila
- cpe:2.3:a:librechat:librechat:0.8.3:rc1:*:*:*:*:*:* Versions 0.8.3 rc1 Vulnerable ·danny-avila
- cpe:2.3:a:librechat:librechat:0.8.3:rc2:*:*:*:*:*:* Versions 0.8.3 rc2 Vulnerable ·danny-avila
Remediation
- Fix · CNA LibreChat (danny-avila) Fixed in 0.8.3
Timeline
- 2026-10-02 Threatist record created from CVE-2026-31943
More danny-avila Librechat vulnerabilities
- TI-2026-25134 LibreChat Exfiltrates Server Secrets via MCP Server URL Injection CVSS 3.1CRITICAL 9.6
- TI-2026-17862 LibreChat MCP Stdio Remote Command Execution CVSS 3.1CRITICAL 9.9
- TI-2026-38976 LibreChat: Missing Resource Parameter Validation in MCP OAuth Flow CVSS 3.1CRITICAL 9.3
- TI-2024-27763 LibreChat through 0.7.4-rc1 has incorrect access control for message updates. CVSS 3.1CRITICAL 9.8
- TI-2024-10347 Path Traversal in danny-avila/librechat CVSS 3.0HIGH 8.8
- TI-2026-25682 In LibreChat 0.8.1-rc2, a logged-in user obtains a JWT for both the LibreChat API and the RAG API. CVSS 3.1CRITICAL 9.0
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences