Description
LibreChat is a ChatGPT clone with additional features. From 0.8.2 to 0.8.2-rc3, The MCP (Model Context Protocol) OAuth callback endpoint accepts the redirect from the identity provider and stores OAuth tokens for the user who initiated the flow, without verifying that the browser hitting the redirect URL is logged in or that the logged-in user matches the initiator. An attacker can send the authorization URL to a victim; when the victim completes the flow, the victim’s OAuth tokens are stored on the attacker’s LibreChat account, enabling account takeover of the victim’s MCP-linked services (e.g. Atlassian, Outlook). This vulnerability is fixed in 0.8.3-rc1.
CVSS Metrics
- Vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
- Attack Vector
- network
- Complexity
- low
- Privileges
- low
- User Action
- required
- Scope
- changed
- Confidentiality
- high
- Integrity
- low
- Availability
- none
- Weaknesses
- CWE-306
Metadata
- Primary Vendor
- LIBRECHAT
- Published
- 3/13/2026
- Last Modified
- 3/17/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
librechat : librechatlibrechat : librechatlibrechat : librechatlibrechat : librechat
AI-Powered Remediation
Generate remediation guidance or a C-suite brief for this vulnerability.