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Public proof of conceptFix available

CVE-2025-69196

A public proof of concept exists; no exploitation attested.

  • Published2026-03-16
  • Fixed in2.14.2
  • WeaknessCWE-1220 · CWE-863

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-03-1619:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2025-69196?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2025-69196?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Jlowin fastmcp
BranchAffectedFixed in
2.14< 2.14.22.14.2

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update Jlowin fastmcp to 2.14.2

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionpoc2026-03-16
  • OpenCVESSVC decisionpoc—
  • CNACVSS 4.07.4read 2026-10-23
  • CNACVSS 3.17.4read 2026-10-23
  • NVDCVSS 3.16.5read 2026-10-23
  • CNAweakness (CWE)CWE-1220, CWE-863read 2026-10-23
  • FIRST EPSSEPSS score0.4 %2026-10-23
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CVSS 4.0 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
Published
2026-03-16
Last Modified
2026-07-15
NVD status
Modified

Frequently asked questions

What is CVE-2025-69196?

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.

Is CVE-2025-69196 actively exploited?

A proof-of-concept exploit exists for CVE-2025-69196, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2025-69196?

CVE-2025-69196 has a CVSS v3 base score of 6.5 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

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