CVE DATABASE  /  CVE-2026-45585

CVE-2026-45585

Summary

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.

CVSS 3.1 breakdown

Weakness type (CWE)

• CWE-77

Affected products

Our coverage

• Microsoft Bans Researcher After 6 Windows Zero-Days Dropped Publicly

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45585
• https://github.com/Nightmare-Eclipse/YellowKey

Data: NIST NVD. NVD last modified 2026-05-22. Always verify against the vendor advisory before acting.