Microsoft Patches RoguePlanet Vulnerability in Defender Antivirus After Public Disclosure

Microsoft released security updates to patch the RoguePlanet vulnerability in its Defender antivirus software nearly a month after the flaw was publicly disclosed. The issue, tracked as CVE-2026-50656 with a CVSS score of 7.8, is a privilege escalation vulnerability in the Microsoft Malware Protection Engine (mpengine.dll), which handles scanning, detection, and cleaning functions. The flaw could allow attackers to gain SYSTEM-level privileges on affected systems. No specific exploitation instances or affected versions were detailed in the report. The update addresses the vulnerability in the core engine component of Microsoft Defender.