CVE-2025-62801 FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

What is CVE-2025-62801?

CVE-2025-62801 is a medium-severity command injection vulnerability in jlowin fastmcp, published on 28 Oct 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-78

Which versions are affected by CVE-2025-62801?

3 open source packages ship an affected version, including fastmcp. It affects 1 product.

Products include Jlowin Fastmcp.

How do I fix CVE-2025-62801?

Upgrade fastmcp to 2.13.0 or later.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

Is CVE-2025-62801 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-62801 exists.

Other vulnerabilities in jlowin fastmcp

• CVE-2026-32871 FastMCP OpenAPI Provider has an SSRF & Path Traversal Vulnerability Critical 10.0
• CVE-2026-27124 FastMCP: Missing Consent Verification in OAuth Proxy Callback Facilitates Confused Deputy Vulnerabilities High 8.2
• CVE-2025-69196 FastMCP OAuth Proxy token reuse across MCP servers High 7.4
• CVE-2025-64340 FastMCP has a Command Injection vulnerability - Gemini CLI Medium 6.7
• CVE-2025-62800 FastMCP vulnerable to reflected XSS in client's callback page Medium 5.3

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-rj5c-58rq-j5g5, PYSEC-2026-1365, ROOT-APP-PYPI-CVE-2025-62801.