CVE-2025-69196
March 16, 2026
FastMCP is the standard framework for building MCP applications. Prior to version 2.14.2, the server does not properly respect the resource parameter submitted by the client in the authorization and token request. Instead of issuing the token explicitly for the MCP server, the token is issued for the base_url passed to the OAuthProxy during initialization. This issue has been patched 2.14.2.
Affected Packages
fastmcp (CONDA):
Affected version(s) >=2.3.4 <2.14.2Fix Suggestion:
Update to version 2.14.2fastmcp (PYTHON):
Affected version(s) >=0.1.0 <2.14.2Fix Suggestion:
Update to version 2.14.2Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
ACTIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.8
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Incorrect Authorization
EPSS
Base Score:
0.01
