CVE-2026-54027: LibreChat: Image Upload Route Bypasses Agent Permission Check — Incomplete Fix for File Upload Authorization
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 toolresources (e.g., context, executecode) 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
LibreChatto a version that resolves this vulnerability.Fixed in 0.8.4-rc1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-54027?
The severity of CVE-2026-54027 is medium with a score of 6.5.
How do I fix CVE-2026-54027?
To fix CVE-2026-54027, upgrade LibreChat to version 0.8.4-rc1 or later where the vulnerability has been addressed.
What does CVE-2026-54027 affect?
CVE-2026-54027 affects the image upload functionality in LibreChat, allowing unauthorized file uploads by authenticated users.
What types of attacks are possible due to CVE-2026-54027?
Due to CVE-2026-54027, attackers can potentially upload malicious files to agents' resources due to inadequate permission checks.
Is CVE-2026-54027 related to file upload vulnerabilities?
Yes, CVE-2026-54027 is specifically related to an incomplete fix for file upload authorization in LibreChat.