CVE-2026-45585

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.

Affected products

Windows

Microsoft Windows 11 24h2

All versions

Microsoft Windows 11 25h2

All versions

Microsoft Windows 11 26h1

All versions

Microsoft Windows Server 2025

All versions

Fix

Available

CVSS 3.1

6.8 MEDIUM

EPSS

1.4% (69th percentile)

Weakness

CWE-77

NVD status

Modified

Published

2026-05-19