Description
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.
CVSS Metrics
- Vector
- CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack Vector
- network
- Complexity
- high
- Privileges
- none
- User Action
- active
- Confidentiality
- undefined
- Integrity
- undefined
- Availability
- undefined
- Weaknesses
- CWE-863
Metadata
- Primary Vendor
- JLOWIN
- Published
- 3/16/2026
- Last Modified
- 3/18/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
jlowin : fastmcp
AI-Powered Remediation
Generate remediation guidance or a C-suite brief for this vulnerability.