Nightmare Eclipse

A security researcher named Nightmare Eclipse has disclosed a Windows zero-day exploit called LegacyHive, enabling attackers to escalate privileges on updated Windows systems. The exploit grants hackers administrative access to these systems.

Nightmare Eclipse, a bug hunter with a reported grudge against Microsoft, disclosed a new zero-day vulnerability called RoguePlanet targeting Microsoft Defender on Windows 10 and 11. The flaw allows local privilege escalation to SYSTEM-level access and is part of seven zero-days the researcher has publicly released, accusing Microsoft of ignoring vulnerability reports and refusing communication. Microsoft initially responded with potential legal threats but later clarified it had 'no intention to pursue action' against security researchers.

Microsoft released a record 200 security patches in June 2026's Patch Tuesday, with 30 critical vulnerabilities and public exploits for three flaws. AI tools are increasingly used to discover bugs, and researcher Nightmare Eclipse disclosed multiple zero-day exploits, including CVE-2026-49160 and CVE-2026-50507, sparking controversy over Microsoft's legal stance on researchers.

Microsoft threatened criminal legal action against security researcher 'Nightmare Eclipse' for publicly disclosing zero-day vulnerabilities without prior coordination. The researcher claimed Microsoft refused to communicate, deleted their security response account, and flagged their GitHub account, escalating a public dispute over vulnerability disclosure practices.

Microsoft is facing criticism for threatening legal action against an individual who disclosed zero-day exploits. Nightmare Eclipse, a user, posted proof-of-concept exploit code, prompting Microsoft to disable their GitHub, GitLab, and Microsoft Security Response Center accounts. Cybersecurity researcher Kevin Beaumont highlighted Microsoft's response as a point of concern.

Disgruntled bug hunter Nightmare Eclipse (Chaotic Eclipse) has released six Windows zero-days, prompting Microsoft to issue a blog post condemning uncoordinated disclosure and threatening legal action. Nightmare claims Microsoft humiliated them by deleting their MSRC account and withholding payment, vowing a major release on July 14.