CVE-2025-64340

Description

FastMCP is the standard framework for building MCP applications. Prior to version 3.2.0, server names containing shell metacharacters (e.g., &) can cause command injection on Windows when passed to fastmcp install claude-code or fastmcp install gemini-cli. These install paths use subprocess.run() with a list argument, but on Windows the target CLIs often resolve to .cmd wrappers that are executed through cmd.exe, which interprets metacharacters in the flattened command string. This issue has been patched in version 3.2.0.

Risk Information

Base Score
6.7
MODERATE
Vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
EPSS Score
Exploitation Probability
0.028

Associated Vulnerability

VulnerabilityOS Platform
Vulnerabilities CVE-2025-64340,CVE-2026-27124,CVE-2026-32871 are fixed in Python-fastmcp 3.2.0Windows
Vulnerabilities CVE-2025-64340,CVE-2026-27124,CVE-2026-32871 are fixed in Python-fastmcp for linux 3.2.0Linux

Patch Details

No records found

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234