A publicly disclosed elevation of privilege vulnerability, tracked as CVE-2026-50656 and nicknamed ‘RoguePlanet’, has been found in the Microsoft Malware Protection Engine within Microsoft Defender. An attacker exploiting this flaw could gain elevated system privileges on affected machines. Microsoft has acknowledged the issue but has not yet released a patch, meaning systems remain exposed whilst a fix is in development.

Security Architect’s Take: With no patch currently available, prioritise compensating controls: ensure Defender is configured with least-privilege service accounts, monitor for anomalous privilege escalation events via Microsoft Sentinel or your SIEM, and consider temporarily increasing alert sensitivity on endpoints running Microsoft Defender until the update is released.

Original advisory: CVE-2026-50656 Microsoft Defender Elevation of Privilege Vulnerability