A new zero-day exploit named RoguePlanet has been discovered targeting Microsoft’s Windows operating system, disclosed by security researcher Nightmare Eclipse. The exploit allows local privilege escalation (LPE) by exploiting a race condition in Microsoft Defender and can facilitate remote code execution (RCE) through deceptive .vhd(x) files. RoguePlanet may also bypass BitLocker encryption. The proof-of-concept has been tested on Windows 10 and Windows 11 systems but does not function on Windows Server, although the researcher believes all Windows Server versions are vulnerable. Following its release, RoguePlanet was confirmed by other researchers to spawn a command prompt with SYSTEM privileges on patched computers. This disclosure comes after Microsoft released patches for earlier exploits by Nightmare Eclipse, including GreenPlasma and YellowKey. The researcher has expressed dissatisfaction with Microsoft’s vulnerability disclosure process, alleging legal action against them and the suspension of their GitHub account, leading to the publication of RoguePlanet under a new account.