Security Researcher Discloses New Windows Zero-Day Bug ShieldBreak

Security researcher Nightmare Eclipse has publicly disclosed a zero-day vulnerability dubbed ShieldBreak that affects Windows 10, Windows 11, and Windows Server 2025.

The exploit leverages a flaw in Windows Defender to allow hackers to escalate permissions to system-wide access, bypassing a previous patch for the RoguePlanet bug.

Microsoft has not yet released a patch for the vulnerability, which was disclosed without prior notice following ongoing disputes between the researcher and the company.