LibreChat: Missing Resource Parameter Validation in MCP OAuth Flow
Priority HIGH 75CWE-346Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-346.
Summary
LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.5, LibreChat's MCP OAuth implementation does not validate that the resource parameter from OAuth Protected Resource metadata (RFC 9728) matches the configured MCP server URL, allowing a malicious MCP server to steal access tokens intended for a legitimate server. This vulnerability is fixed in 0.8.5.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00168 6th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed LibreChat (danny-avila): 0.8.5
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
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 0.8.5 | 0.8.5 | Patch available | CNA |
- LibreChat Vendordanny-avila Affected before 0.8.5 Fixed in 0.8.5 Patch available CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:* | up to 0.8.4 | Vulnerable | danny-avila |
| cpe:2.3:a:librechat:librechat:0.8.5:rc1:*:*:*:*:*:* | 0.8.5 rc1 | Vulnerable | danny-avila |
- cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:* Versions up to 0.8.4 Vulnerable ·danny-avila
- cpe:2.3:a:librechat:librechat:0.8.5:rc1:*:*:*:*:*:* Versions 0.8.5 rc1 Vulnerable ·danny-avila
Remediation
- Fix · CNA LibreChat (danny-avila) Fixed in 0.8.5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-54030
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-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
- TI-2025-42676 LibreChat is vulnerable to Server-Side Request Forgery due to missing restrictions CVSS 3.1CRITICAL 9.1
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences