Microsoft Releases Mitigation for YellowKey BitLocker Bypass CVE-2026-45585 Exploit
May 20, 2026
Vulnerability / Encryption
Microsoft on Tuesday released a mitigation for a BitLocker bypass vulnerability named YellowKey following its public disclosure last week. The zero-day flaw, now tracked as CVE-2026-45585 , carries a CVSS score of 6.8. It has been described as a BitLocker security feature bypass. "Microsoft is aware of a security feature bypass vulnerability in Windows publicly referred to as 'YellowKey,'" the tech giant said in an advisory. "The proof of concept for this vulnerability has been made public, violating coordinated vulnerability best practices." The issue impacts Windows 11 version 26H1 for x64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for x64-based Systems, Windows Server 2025, and Windows Server 2025 (Server Core installation). YellowKey was disclosed by a security researcher named Chaotic Eclipse (aka Nightmare-Eclipse). It essentially involves placing specially crafted 'FsTx' files on a USB driv...