Microsoft closes book on Nightmare Eclipse's RoguePlanet zero-day

Microsoft has quietly fixed the “RoguePlanet” zero-day in Microsoft Defender, closing the latest hole exposed by security researcher Nightmare Eclipse after months of public sparring over the company's handling of vulnerability reports. The vulnerability, tracked as CVE-2026-50656, was addressed through an update to the Microsoft Malware Protection Engine rather than via its monthly Patch Tuesday bundle. Microsoft said customers should ensure they're running the latest engine version