VulnerabilityModified
CVE-2025-69196
FastMCP is the standard framework for building MCP applications.
HIGH 7.4EPSS 0.36%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 4.0
- 7.4 HIGHCVSS: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/M
- EPSS
- 0.36% probability · 29th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-863, CWE-1220
- Affected
- jlowin/fastmcp
- Source
- security-advisories@github.com
References
- https://github.com/PrefectHQ/fastmcp/security/advisories/GHSA-5h2m-4q8j-pqpjExploit, Mitigation, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:36350
- https://access.redhat.com/security/cve/CVE-2025-69196
- https://bugzilla.redhat.com/show_bug.cgi?id=2448179
- https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-69196.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.