Microsoft Patches RoguePlanet Defender Flaw That Can Grant SYSTEM Privileges

Microsoft patched a high-severity privilege-escalation flaw in the Microsoft Malware Protection Engine (CVE-2026-50656, "RoguePlanet") that allows an attacker to spawn a SYSTEM shell and execute arbitrary code; the researcher Chaotic Eclipse demonstrated a working exploit that functions on up-to-date Windows systems. The researcher also reported that the new Defender "defense-in-depth" updates can cause an 8-byte data leak via Zone.Identifier Alternate Data Streams and described an SMB-based technique that can lock files and exhaust disk space, producing a denial-of-service scenario; Microsoft said it is investigating and released an updated engine version to remediate the issue.