CVE-2025-62801Public exploit

Local command execution via unescaped Cursor server name

Published Oct 28, 2025 · Updated Oct 28, 2025

OS command injection in FastMCP before 2.13.0 allows local users to execute arbitrary commands when Windows installs a crafted MCP in Cursor. generate_cursor_deeplink embeds server_name verbatim in a URI that open_deeplink passes through shell=True to cmd.exe, allowing metacharacters to escape the start command. Exploitation requires control of the MCP server name and a user or automated process to run the Cursor installation command; successful execution grants commands the installer's privileges.

CVSS severity5.4
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in FastMCP before 2.13.0 allows local users to execute arbitrary commands when Windows installs a crafted MCP in Cursor. generate_cursor_deeplink embeds server_name verbatim in a URI that open_deeplink passes through shell=True to cmd.exe, allowing metacharacters to escape the start command. Exploitation requires control of the MCP server name and a user or automated process to run the Cursor installation command; successful execution grants commands the installer's privileges.

The record

CVE
CVE-2025-62801
Published
Oct 28, 2025
Updated
Oct 28, 2025
Vendor
Prefect Technologies, Inc.
Product
FastMCP
Classifications
CWE-78, T1204.002, T1059.003
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.13.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Prefect Technologies, Inc. · FastMCPversion=< 2.13.0

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.4GitHub, Inc.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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1204.002Malicious File
T1059.003Windows Command Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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