After Microsoft threatened legal action, a security researcher publishes a new Windows zero-day bug (2 minute read)

2026-08-14

ShieldBreak is a Windows Defender privilege-escalation exploit. A victim must run the supplied app. It affects Windows 10, Windows 11 25H2, and Windows Server 2025. Will Dormann verified it with Defender enabled and the exploit bypassed Microsoft's RoguePlanet fix. Microsoft is investigating and has not released a patch.