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TI-2025-38984 Aliases CVE-2025-62801GHSA-rj5c-58rq-j5g5

FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

Priority MEDIUM 60CWE-78Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
Active
Attack complexity
Low
Attack requirements
Present
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-78.

Summary

FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0, a command-injection vulnerability lets any attacker who can influence the server_name field of an MCP execute arbitrary OS commands on Windows hosts that run fastmcp install cursor. This vulnerability is fixed in 2.13.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00227 13th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed fastmcp (jlowin): 2.13.0fastmcp (PyPI): 2.13.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
jlowinfastmcpbefore 2.13.02.13.0Patch availableCNA
—fastmcp (PyPI)before 2.13.02.13.0Patch availableGHSA-rj5c-58rq-j5g5
  • fastmcp Vendorjlowin Affected before 2.13.0 Fixed in 2.13.0 Patch available CNA
  • fastmcp (PyPI) Vendor— Affected before 2.13.0 Fixed in 2.13.0 Patch available GHSA-rj5c-58rq-j5g5

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:jlowin:fastmcp:*:*:*:*:*:*:*:*before 2.13.0Vulnerablejlowin
  • cpe:2.3:a:jlowin:fastmcp:*:*:*:*:*:*:*:* Versions before 2.13.0 Vulnerable ·jlowin

Remediation

  • Fix · CNA fastmcp (jlowin) Fixed in 2.13.0
  • Fix · GHSA-rj5c-58rq-j5g5 fastmcp (PyPI) Fixed in 2.13.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-62801
  2. 2026-10-03 Alias added: GHSA-rj5c-58rq-j5g5

References

Exploit 1

Advisory 1

Other 1

  • TI-2026-25332 FastMCP OpenAPI Provider has an SSRF & Path Traversal Vulnerability CVSS 4.0CRITICAL 10.0
  • TI-2026-21575 FastMCP: Missing Consent Verification in OAuth Proxy Callback Facilitates Confused Deputy Vulnerabilities CVSS 4.0HIGH 8.2
  • TI-2025-39774 FastMCP has a Command Injection vulnerability - Gemini CLI CVSS 3.1HIGH 7.8
  • TI-2025-42650 FastMCP OAuth Proxy token reuse across MCP servers CVSS 4.0HIGH 7.4
  • TI-2025-38983 FastMCP vulnerable to reflected XSS in client's callback page CVSS 4.0MEDIUM 5.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences