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Missing AuthenticationWeakness · CWE-306

CVE-2026-48989

HIGH · 8.9 CVSS v4.0 Published 2026-06-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
98/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Windows-MCP versions before 0.7.5 exposed the MCP control plane in certain HTTP modes without authentication while enabling wildcard CORS settings (allow_origins=*, allow_methods=*, allow_headers=*). Since the same server exposed a PowerShell tool that executes caller-controlled commands as the Windows user running Windows-MCP, attackers from arbitrary origins or non-browser clients could reach the control plane and achieve arbitrary PowerShell execution.

MitigationUpgrade Windows-MCP to version 0.7.5 or later, which addresses the authentication bypass and restrictive CORS configuration.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
Authentication
X
User interaction
None
Scope
X

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Windows-MCP version
    Locate the Windows-MCP installation and check its version number or package metadata. Common locations include the installation directory, package.json, or the executable's version info. Compare against the affected range (before 0.7.5).
    Affected if Version is below 0.7.5
  2. Determine the server transport mode
    Inspect the Windows-MCP configuration file or startup parameters to identify which transport mode is enabled (HTTP, SSE, or stdio). Look for configuration keys related to server transport or HTTP binding.
    Affected if HTTP mode is enabled (not SSE or stdio)
  3. Inspect CORS configuration
    Examine the CORS settings in the Windows-MCP configuration. Look for the specific allow_origins, allow_methods, and allow_headers directives and verify if any are set to wildcard (*)
    Affected if All three CORS settings are set to wildcard (*): allow_origins=*, allow_methods=*, allow_headers=*
  4. Verify PowerShell tool is exposed
    Check the Windows-MCP tool configuration to determine if the PowerShell execution tool is enabled and accessible through the MCP server. This tool is required for the arbitrary command execution impact.
    Affected if PowerShell tool is enabled and accessible via the MCP server

Environment is affected only if Windows-MCP version is below 0.7.5 AND HTTP transport mode is active AND wildcard CORS settings are configured AND the PowerShell tool is enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Windows-MCP to version 0.7.5 or later, which addresses the authentication bypass and restrictive CORS configuration.

Recommended fix High confidence

0.7.5

  1. 1. Identify the current Windows-MCP version by checking the installed package or running 'windows-mcp --version'
  2. 2. Backup all existing Windows-MCP configuration files and settings
  3. 3. If using a package manager (pip, npm, etc.), upgrade to version 0.7.5: 'pip install windows-mcp==0.7.5' or the equivalent for your package manager
  4. 4. If using a pre-built binary, download the v0.7.5 release from the official repository
  5. 5. Restore your configuration files to the updated installation
  6. 6. Restart the Windows-MCP service
  7. 7. Verify the new version is running and confirm authentication is now required for the control plane

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-48989 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data