Microsoft Defender: Critical Patch Bypass for CVE-2026-50656 RoguePlanet
A critical patch bypass vulnerability has been identified within the Microsoft Defender Malware Protection Engine, specifically impacting systems previously remediated for CVE-2026-50656 (RoguePlanet). While Microsoft released Engine version v1.1.26060.3008 in July 2026 to mitigate a race condition and improper link resolution in mpengine.dll, a new exploit chain dubbed "ShieldBreak" has successfully circumvented this fix. Discovered by researcher Chaotic Eclipse, the ShieldBreak proof-of-concept (PoC) allows local, low-privilege users to escalate privileges to NT AUTHORITY\SYSTEM. This vulnerability presents an immediate risk of full system compromise, as the PoC is publicly available, facilitating rapid exploitation of patched environments.