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TI-2026-38974 Aliases CVE-2026-54027

LibreChat: Image Upload Route Bypasses Agent Permission Check — Incomplete Fix for File Upload Authorization

Priority MEDIUM 62CWE-862Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-862.

Summary

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.4-rc1, the POST /api/files/images endpoint allows any authenticated user to upload files into any agent's tool_resources (e.g., context, execute_code) without verifying ownership or EDIT permission on the target agent. A permission check was added to the POST /api/files route in a previous patch, but the image upload route was never updated with the same check. An attacker can simply use the image endpoint instead of the file endpoint to bypass the authorization entirely. This vulnerability is fixed in 0.8.4-rc1.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00324 25th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed LibreChat (danny-avila): 0.8.4-rc1

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

VendorProductAffected versionsFixed inStatusSource
danny-avilaLibreChatbefore 0.8.4-rc10.8.4-rc1Patch availableCNA
  • LibreChat Vendordanny-avila Affected before 0.8.4-rc1 Fixed in 0.8.4-rc1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:*up to 0.8.3Vulnerabledanny-avila
  • cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:* Versions up to 0.8.3 Vulnerable ·danny-avila

Remediation

  • Fix · CNA LibreChat (danny-avila) Fixed in 0.8.4-rc1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-54027

References

Exploit 1

  • 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
See all 50 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences