The researcher known as "Nightmare-Eclipse" published a proof-of-concept (PoC) exploit for the Windows Defender vulnerability in early June after dropping several other Microsoft zero-days.
July 9, 2026
Microsoft has tackled yet another zero-day vulnerability published by a disgruntled security researcher with a vendetta against the software giant.
On Wednesday, Microsoft issued an out-of-band patch for RoguePlanet, an elevation-of-privilege vulnerability in Windows Defender, tracked as CVE-2026-50656. The high-severity flaw, which received a 7.8 CVSS score from Microsoft, could allow an attacker to escalate privileges on a Windows device from a basic user to the highest SYSTEM-level access, which would give them complete control over the device.
RoguePlanet was initially published, along with a proof-of-concept (PoC) exploit, by an anonymous security researcher known as "Nightmare-Eclipse," who has been embroiled in a public feud with Microsoft for several months. The dispute began in April when the researcher published an exploit for another privilege-escalation flaw in Windows Defender, dubbed "BlueHammer" and tracked as CVE-2026-33825, out of frustration with Microsoft's Security Response Center (MSRC).
