CVE-2025-64340FastMCP is the standard framework for building MCP applications.
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.8 HIGH (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-78
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jul 24, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
jlowin fastmcp jlowin:fastmcp | before 3.2.0 | NVD |
References
- https://github.com/PrefectHQ/fastmcp/pull/3522issue-tracking, patch
- https://github.com/PrefectHQ/fastmcp/security/advisories/GHSA-m8x7-r2rg-vh5gexploit, patch, vendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.