CVE-2025-69196
FastMCP OAuth Proxy token reuse across MCP servers
- State
- Published
- Severity
- 7.4 High
- Published
- Mar 16, 2026
- Updated
- Jul 15, 2026
- Reserved
- Dec 29, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.4 High | 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 | GitHub_M |
| 3.1 | 7.4 High | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N | redhat-SADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
fastmcpjlowin |
|
References
- https://github.com/PrefectHQ/fastmcp/security/advisories/GHSA-5h2m-4q8j-pqpj
- https://access.redhat.com/security/cve/CVE-2025-69196vdb-entry
- RHBZ#2448179issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-69196.json
- https://access.redhat.com/errata/RHSA-2026:36350vendor-advisory
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