CVE-2026-48989CWE-306

Windows-MCP: HTTP transports expose unauthenticated PowerShell control with wildcard CORS

High · published June 17, 2026

CVSS v4.0
8.9
EPSS
1%
Percentile
52.4
In the wild
Unconfirmed
What it is

Windows-MCP is an open-source project that integrates AI agents with Windows. In versions prior to 0.7.5, certain HTTP modes exposed the MCP control plane without authentication while enabling wildcard CORS (allow_origins=*, allow_methods=*, allow_headers=*). Because the same server also exposed a PowerShell tool that executes caller-controlled commands as the Windows user running Windows-MCP, attackers could reach the control plane from arbitrary origins or non-browser clients and achieve arbitrary PowerShell execution. This issue was fixed in version 0.7.5.

The record
Technical detail
CVSS v4.0
8.9 · HIGH
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
EPSS
0.00694 · 52.4th percentile
Weakness
CWE-306 · Missing Authentication for Critical Function
Published
2026-06-17T21:02Z
EPSS history
Timeline
  • 17 JUN 21:02Z
    Windows-MCP: HTTP transports expose unauthenticated PowerShell control with wildcard CORS
    cvelistv5