CVE-2026-54027

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

MEDIUM
6.5
CVSS Score
Published: June 25, 2026 at 03:52 PM UTC
Updated: October 25, 2026 at 10:10 PM UTC
2 products affected across 2 vendorsLibreChatLibreChat

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 0.8.3
v < 0.8.4-rc1
Affected range stops below 0.8.4-rc1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/danny-avila/LibreChat/security/advisories/GHSA-c55r-p24w-hcj5

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-862

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