Important CVSS 6.8 EPSS 0.00846 📢 Publicly disclosed 2026-05 archive

Executive 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.

Overview

6.8
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
More Likely
MS Exploit Likelihood
Category Security Feature Bypass
Released May 12 2026
Last Updated May 12 2026
Publicly Disclosed Yes
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.00846 — 0.53213 percentile
NVD CVSS 6.8 MEDIUM — matches MSRC

CVSS Vector

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:W/RC:C
ATTACK VECTOR
Physical
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Workaround
REPORT CONFIDENCE
Confirmed
Temporal Score: 6.3

EPSS Score

0.00846
probability of exploitation in the next 30 days
0.53213 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

5 affected products
Product KB Article Severity Impact Restart Required
Windows 11 Version 24H2 for x64-based Systems 5094126 (Security Update) Important Security Feature Bypass Yes
Windows 11 Version 25H2 for x64-based Systems 5094126 (Security Update) Important Security Feature Bypass Yes
Windows 11 version 26H1 for x64-based Systems 5095051 (Security Update) Important Security Feature Bypass Yes
Windows Server 2025 5094125 (Security Update) Important Security Feature Bypass Yes
Windows Server 2025 (Server Core installation) 5094125 (Security Update) Important Security Feature Bypass Yes

Patches

3 patches
Article Type Restart
5094126 Security Update Yes
5095051 Security Update Yes
5094125 Security Update Yes

Known Exploits

Acknowledgments

None