---
schema_version: '1.0'
id: security-20260708-acd1c4
url: https://osv.dev/vulnerability/PYSEC-2026-1365
url_hash: acd1c48e3b733bfe6695b6eee8fe663043eed48cf99cf5185c332d72c3897051
canonical_url: https://osv.dev/vulnerability/PYSEC-2026-1365
source: osv:pypa
category: security/library
category_raw: cve/library
region: null
tags:
- cve
- CVE-2025-62801
- PYSEC-2026-1365
- severity:CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- fastmcp
- PyPI
lang: en
published_at: '2026-07-07T16:03:08Z'
fetched_at: '2026-07-08T15:37:25Z'
updated_at: '2026-07-11T06:37:45Z'
status: published
content_hash: 6d72f25334613db19fd4d4ba797fa040b94f893dbd6668c317a1f35bd3809924
license_note: full
summary: FastMCP vulnerable to windows command injection in FastMCP Cursor installer
  via server_name
summary_source: rss
summary_en: FastMCP vulnerable to windows command injection in FastMCP Cursor installer
  via server_name
entities:
- name: Windows
  type: artifact
- name: Command and Conquer Generals
  type: artifact
related_auto:
- name: Total_War_EMPIRE_Definitive_Edition
  type: content
  weight: 1.0
title: 'CVE-2025-62801: FastMCP vulnerable to windows command injection in FastMCP
  Cursor installer via server_name'
---

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

## TL;DR
FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

## Key Points
- cve / CVE-2025-62801 / PYSEC-2026-1365 / severity:CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N / fastmcp / PyPI

## Details
**Severity:** CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
**Advisory:** PYSEC-2026-1365 (CVE-2025-62801)

**Affected (your watchlist):**
- `PyPI:fastmcp` 2.11.3 → fixed in 2.13.0 [docker/docker-portal+portal]

**Details:**
### Summary
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

### Details
1. generate_cursor_deeplink(server_name, …) embeds server_name verbatim in a cursor://…?name= query string.
2. open_deeplink() is invoked with shell=True only on Windows. That calls cmd.exe /c start <deeplink>.
3. Any cmd metacharacter inside server_name (&, |, >, ^, …) escapes the start command and spawns an attacker-chosen process.

### PoC
server.py 
```

import random
from fastmcp import FastMCP

mcp = FastMCP(name="test&calc")

@mcp.tool
def roll_dice(n_dice: int) -> list[int]:
    """Roll `n_dice` 6-sided dice and return the results."""
    return [random.randint(1, 6) for _ in range(n_dice)]

if __name__ == "__main__":
    mcp.run()
```

then run in the terminal:
`fastmcp install cursor server.py`

### Impact
OS Command / Shell Injection (CWE-78)
Every Windows host that runs fastmcp install cursor is at risk. Developers on their local workstations, CI/CD agents and corporate build machines alike.

**References:**
- https://github.com/jlowin/fastmcp/security/advisories/GHSA-rj5c-58rq-j5g5
- https://nvd.nist.gov/vuln/detail/CVE-2025-62801
- https://github.com/jlowin/fastmcp
- https://pypi.org/project/fastmcp
- https://github.com/advisories/GHSA-rj5c-58rq-j5g5

_Data: OSV.dev (upstream: pypa) — https://osv.dev/vulnerability/PYSEC-2026-1365_

## Source
元記事: [CVE-2025-62801: FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name](https://osv.dev/vulnerability/PYSEC-2026-1365) — published 2026-07-07T16:03:08Z