MICROSOFT has released a security update to address a zero-day vulnerability named RoguePlanet, tracked as CVE-2026-50656, in Microsoft Defender. This Elevation of Privilege (EoP) vulnerability allows attackers to gain complete control over systems if they exploit it from a standard user account. The fix comes with an update to the Microsoft Malware Protection Engine (version 1.1.26060.3008). Users running another antivirus while Defender is off are not impacted.
Most users are already protected due to automatic updates of Defender. Checking the engine version can confirm if systems are updated; version 1.1.26060.3008 or higher is secure.