A security researcher known as Nightmare Eclipse has released “RoguePlanet,” a new Microsoft Defender zero-day exploit that can spawn a command prompt with SYSTEM privileges on fully patched Windows 10 and Windows 11 devices. The disclosure follows a series of disputed Windows zero-day releases and comes after Microsoft patched two other flaws during the June 2026 Patch Tuesday update. #RoguePlanet #NightmareEclipse #MicrosoftDefender #Windows10 #Windows11
Keypoints
- Nightmare Eclipse released the RoguePlanet Microsoft Defender zero-day exploit.
- The flaw affects fully patched Windows 10 and Windows 11 systems.
- Successful exploitation can spawn a SYSTEM-level command prompt.
- ThreatLocker reproduced the exploit and confirmed it on patched Windows 11.
- The release is part of an ongoing dispute with Microsoft over vulnerability disclosure.