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Windows-MCP CVE-2026-48989

HIGH
Missing Authentication for Critical Function (CWE-306)
2026-06-17 GitHub_M GHSA-vrxg-gm77-7q5g
Authentication Bypass Microsoft Windows Mcp
8.9
CVSS 4.0 · Vendor: GitHub_M
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Severity by source

Vendor (GitHub_M) PRIMARY
8.9 HIGH
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vuln.today AI
9.8 CRITICAL

HTTP control plane is network-reachable with wildcard CORS and no auth provider, and the PowerShell tool yields full C/I/A impact within the user's security context, so no scope change.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
X

Lifecycle Timeline

3
Source Code Evidence Fetched
Jun 17, 2026 - 22:15 vuln.today
Analysis Generated
Jun 17, 2026 - 22:15 vuln.today
CVE Published
Jun 17, 2026 - 21:02 cve.org
HIGH 8.9

DescriptionCVE.org

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.

AnalysisAI

Unauthenticated remote PowerShell execution in CursorTouch Windows-MCP prior to version 0.7.5 allows attackers to reach the MCP control plane over HTTP and invoke the built-in PowerShell tool as the Windows user running the server. The flaw stems from SSE and streamable-http transports being built without an auth provider while wildcard CORS (allow_origins=*) is applied, opening the path to cross-origin browser pages and any non-browser HTTP client. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
Identify Windows-MCP HTTP transport endpoint
Delivery
Lure victim to attacker origin or reach bound port directly
Exploit
Bypass Same-Origin Policy via wildcard CORS or DNS rebinding
Execution
Initialize unauthenticated MCP session at /mcp
Persist
Invoke tools/call for PowerShell with encoded command
Impact
Execute arbitrary PowerShell as the Windows user
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Vulnerability AssessmentAI

Exploitation Windows-MCP must be launched with the sse or streamable-http transport (the default stdio transport is not affected) in a version below 0.7.5; no authentication, credentials, or user interaction on the target are required once the HTTP listener is reachable. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The CVSS 4.0 vector AV:N/AC:L/AT:N/PR:N/UI:N with VC/VI/VA all High and Exploit Maturity Proof-of-Concept aligns with the description: a network-reachable control plane reaches arbitrary command execution with no authentication and no user interaction, which is a top-priority profile. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario A victim runs Windows-MCP with the streamable-http or sse transport bound to localhost:8000 while browsing the web; an attacker-controlled page issues a fetch to http://localhost:8000/mcp, the wildcard CORS response lets the browser read the result, and the attacker initializes an MCP session and calls tools/call for PowerShell with an encoded command that downloads and runs a second-stage payload as the logged-in Windows user. Alternatively, a non-browser attacker who can reach the bound interface (or who wins a DNS-rebinding race against an unvalidated Host header) does the same directly with curl. …
Remediation Vendor-released patch: 0.7.5 - upgrade via uvx windows-mcp@0.7.5 serve or pip install --upgrade windows-mcp as documented at https://github.com/CursorTouch/Windows-MCP/releases/tag/v0.7.5. … Detailed patch versions, workarounds, and compensating controls in full report.
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Recommended ActionAI

Within 24 hours: Identify all CursorTouch Windows-MCP deployments running versions before 0.7.5 and restrict HTTP access via network firewall rules; enable comprehensive logging of control plane activity. …

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Threat intelligence, references, and detailed analysis are available after sign-in.

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CVE-2026-48989 vulnerability details – vuln.today
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