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Microsoft Security Response CenterCVE-2026-45585

Windows BitLocker Security Feature Bypass Vulnerability

Microsoft is aware of a security feature bypass vulnerability in Windows publicly referred to as "YellowKey". The proof of concept for this vulnerability has been made public violating coordinated vulnerability best practices. We are issuing this CVE to provide mitigation guidance that can be implemented to protect against this vulnerability until the security update is made available. Mitigation FAQs Should I leverage the temporary mitigation? Microsoft recommends that you consider implementing these mitigations if you are concerned your devices and data are at risk of being compromised or stolen. For example, if your organization’s employees take their work devices home or on business travel. What impact to service availability/management could be caused by implementing the mitigations? Implementing these mitigations will not impact service availability or management operations. Do customers need to revert the changes made to mitigate the vulnerability once the security update to protect against this vulnerability is available? No. The security update will maintain the mitigation's behavior once the security update is installed. I am using TPM+PIN, am I at risk of this vulnerability being exploited No, if you are using TPM+PIN the vulnerability is not exploitable.

6.8CVSS out of 10High severity
Scope

What the vendor says is affected

  • Windows Server 2025 (Server Core installation)
  • Windows 11 Version 25H2 for x64-based Systems
  • Windows 11 Version 24H2 for x64-based Systems
  • Windows Server 2025
  • Windows 11 version 26H1 for x64-based Systems

Versions the vendor lists as fixed

  • 10.0.26100.32995
  • 10.0.26200.8655
  • 10.0.26100.8655
  • 10.0.28000.2269
Next step

What the vendor recommends

Install KB5094125. Install KB5094126. Install KB5095051.

Review the complete instructions on the vendor's site
Timeline

When this advisory changed

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Updated by Microsoft Security Response Center

    The vendor changed the advisory after it was first published.

  3. Added to SecurityAlert

    We collected the advisory from the official source.

Vulnerabilities

CVEs named in this advisory