CVE-2026-54027

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 63/100
Published: 2026-06-25 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: Unchanged
C: None
I: High
A: None

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
librechat librechat < 0.8.3

References & Advisories (1)

Bug Bounty Relevance

63 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

6.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS — Exploitation Probability

0.32%
Raw Score 0.003240
Percentile 25.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00324
2026-10-28
0.00324

Intelligence Sources

nvd ref →