CVE-2025-62801: PYSEC-2026-1365 - FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

CVE-2025-62801 · Severity: high · CVSS 7.8 · Published 2025-10-28

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.

Technologies: fastmcp (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2025-62801 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2025-62801 being exploited in the wild.
How severe is CVE-2025-62801?
High severity, with a CVSS score of 7.8, published 28 October 2025.
Which products and versions are affected?
fastmcp (PyPI) ECOSYSTEM:introduced=0,fixed=2.13.0.
Is there a fix for CVE-2025-62801?
Yes. fastmcp (PyPI): upgrade to 2.13.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2025-62801?
Check whether you run Jlowin Fastmcp or fastmcp (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • fastmcp (PyPI): upgrade to 2.13.0 or later
    pip install "fastmcp>=2.13.0"

Affected products

  • Jlowin Fastmcp
  • fastmcp (PyPI) ECOSYSTEM:introduced=0,fixed=2.13.0

Identifiers

  • CVE-2025-62801
  • GHSA-rj5c-58rq-j5g5
  • PYSEC-2026-1365

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