Microsoft Reins in RoguePlanet Zero-Day Threat

Microsoft has released an urgent out-of-band patch for a high-severity zero-day vulnerability in Windows Defender, identified as CVE-2026-50656 and named RoguePlanet. The flaw allows attackers to escalate privileges from a regular user to SYSTEM-level access, granting full control over the device. The vulnerability was disclosed by an anonymous researcher known as Nightmare-Eclipse, who has been involved in a public dispute with Microsoft over several months. Despite the availability of a proof-of-concept exploit, there is currently no evidence that the flaw has been exploited in the wild. However, experts warn that the vulnerability poses significant risks, especially if used in conjunction with other initial access methods.