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

Source: https://junglewise.ai/threats/cve-2025-62801-fastmcp-vulnerable-to-windows-command-injection-in-fastmcp-cursor  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-10-28  
License: CC BY 4.0 with a link back

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)](https://junglewise.ai/threats/technologies/fastmcp). Vendors: [PyPI](https://junglewise.ai/threats/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

  ```sh
  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

## Related threats

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- [FastMCP OAuth provider missing issuer binding in M2M credential exchange](https://junglewise.ai/threats/fastmcp-mcp-client-wrappers-construct-m2m-oauth-providers-without-af21ca1f)
- [FastMCP confused deputy vulnerability in OAuthProxy callback](https://junglewise.ai/threats/cve-2026-27124-fastmcp-confused-deputy-vulnerability-in-oauthproxy-callback)
- [PrefectHQ FastMCP command injection in CLI install on Windows](https://junglewise.ai/threats/cve-2025-64340-prefecthq-fastmcp-command-injection-in-cli-install-on-windows)
- [PrefectHQ FastMCP path traversal and SSRF in OpenAPIProvider](https://junglewise.ai/threats/cve-2026-32871-prefecthq-fastmcp-path-traversal-and-ssrf-in-openapiprovider)