CVE-2025-64340 - CVE House
Back to Database
Status published Medium CVE-2025-64340

FastMCP has a Command Injection vulnerability - Gemini CLI

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2025-64340

Credits & Attribution

No credits recorded in the NVD database.

References

More from jlowin

View All →
CVE-2025-69196
FastMCP OAuth Proxy token reuse across MCP servers
High 7.4
CVE-2025-62801
FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name
Medium 5.4
CVE-2025-62800
FastMCP vulnerable to reflected XSS in client's callback page
Medium 5.3

Affected Vendor

Affected Software

fastmcp
Vulnerable Versions:
< 3.2.0

Timeline

Official Publish: April 3rd, 2026
Last Modified: April 3rd, 2026
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H

Weaknesses (CWE)

CWE-78

MITRE ATT&CK TTPs

T1190 Exploit Public-Facing Application
Initial Access
T1059 Command and Scripting Interpreter
Execution
T1068 Exploitation for Privilege Escalation
Privilege Escalation
T1005 Data from Local System
Collection
T1041 Exfiltration Over C2 Channel
Exfiltration