Microsoft Patches RoguePlanet Defender Flaw That Can Grant SYSTEM Privileges
Microsoft has released security updates for a Defender vulnerability known as RoguePlanet, nearly a month after details of the flaw became public. The vulnerability, tracked as CVE-2026-50656 (CVSS score: 7.8), is a privilege escalation issue in the Microsoft Malware Protection Engine ("mpengine.dll"), which provides scanning, detection, and cleaning capabilities for its antivirus and antispyware software. The issue has been remediated in Microsoft Malware Protection Engine version 1.1.26060.3008, along with defense-in-depth updates to harden unspecified security-related features. RoguePlanet was first disclosed by a security researcher named Chaotic Eclipse (aka Nightmare-Eclipse), describing it as a race condition that could be abused to spawn a shell with SYSTEM-level privileges. This, in turn, grants the attacker the ability to run arbitrary code or perform unauthorized actions. The exploit has been found to work on systems running up-to-date versions of Wind...
Jul 09, 2026