Microsoft Acknowledges RoguePlanet Zero-Day Vulnerability in Defender

Microsoft has confirmed a critical zero-day vulnerability in Microsoft Defender, identified as CVE-2026-50656, which allows for local privilege escalation. The flaw, dubbed 'RoguePlanet,' was disclosed by security researcher Nightmare Eclipse and has a CVSS score of 7.8. It exploits a race condition in Defender, enabling attackers to gain system privileges without user interaction. Microsoft is actively working on a security patch to address this vulnerability. The vulnerability affects Windows 10 and Windows 11 systems with the June 2026 patches installed. A proof-of-concept exploit has been released, demonstrating the ease of exploitation. Microsoft has advised users to remain vigilant until a patch is available.

Key Points: • CVE-2026-50656 is a critical zero-day vulnerability in Microsoft Defender. • The vulnerability allows local privilege escalation without user interaction. • Microsoft is actively developing a patch to address the issue.