🛡️ **SHIELDBREAK: Microsoft Defender Privilege Escalation Zero-Day — Patch In Development**
Published Monday, August 17, 2026 at 04:26 AM PT BLUF: Microsoft Defender contains a critical privilege escalation zero-day (ShieldBreak) enabling local attackers to escalate to SYSTEM privileges. Public proof-of-concept exists. Microsoft is developing a patch; no release timeline announced. All Windows systems running Defender are potentially affected until update is published. DETAILS: Vulnerability: Local privilege escalation in Microsoft Defender; allows authenticated local attackers to gain SYSTEM-level access PoC status: Public exploit code available demonstrating full SYSTEM privilege escalation Bypass chain: ShieldBreak circumvents Microsoft’s prior RoguePlanet patch, indicating active evasion of existing mitigations Patch status: In development; deployment timeline and affected Defender versions not yet specified by Microsoft Attribution: Disclosed by Nightmare Eclipse; confirmed by multiple security researchers IMPACT: ...