Microsoft Reins in RoguePlanet Zero-Day Threat

Microsoft issued an out-of-band patch for RoguePlanet (CVE-2026-50656), a Windows Defender elevation-of-privilege flaw (CVSS 7.8) for which a public proof-of-concept was published by a researcher known as "Nightmare-Eclipse"; exploitation requires local access but can elevate a standard user to SYSTEM and enable tampering with security tooling and persistence. Microsoft says no confirmed in-the-wild exploitation, while Qualys reports attacks; organizations are advised to apply the Microsoft Malware Protection Engine update, harden endpoint local execution controls, and monitor for privilege-escalation indicators.