CVE-2025-64340
MEDIUMFastMCP <3.2.0 Gemini CLI Install - Command Injection
Title source: manualDescription
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.
References (2)
Core 2
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/PrefectHQ/fastmcp/security/advisories/GHSA-m8x7-r2rg-vh5g
X_Refsource_Misc x_refsource_misc
https://github.com/PrefectHQ/fastmcp/pull/3522
Scores
CVSS v3
6.7
EPSS
0.0001
EPSS Percentile
1.0%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
total
Details
CWE
CWE-78
Status
published
Products (2)
jlowin/fastmcp
< 3.2.0 (2 CPE variants)
pypi/fastmcp
0 - 3.2.0PyPI
Published
Apr 03, 2026
Tracked Since
Apr 03, 2026