Researcher Chaotic Eclipse Unleashes Zero-Day PoC Wave: ShieldCrash Defender Patch Bypass, NVIDIA GreenSection, CrowdStrike FalconFlank

Zero-day researcher Chaotic Eclipse (aka Nightmare Eclipse/MSNightmare) released a week-long run of PoCs: ShieldCrash bypasses the Microsoft Defender ShieldBreak patch (CVE-2026-69414) to read files as SYSTEM, GreenSection hits an unpatched NVIDIA…

Between September 7 and 10, 2026, researcher Chaotic Eclipse — also known as Nightmare Eclipse and MSNightmare — published a series of zero-day proof-of-concept exploits against major security products. The dominant story is ShieldCrash, released September 9: a PoC showing Microsoft's patch for the ShieldBreak elevation-of-privilege flaw in the Microsoft Malware Protection Engine (CVE-2026-69414, CVSS 7.8, fixed September 3, 2026 in engine version 1.1.26080.3, which updates automatically) can be bypassed. The PoC demonstrates arbitrary file reads with SYSTEM privileges on fully patched Windows 10, Windows 11, and Windows Server — enough to dump the SAM database — but does not enable arbitrary writes, code execution, or a full SYSTEM shell. It is the third bypass in a chain: ShieldBreak itself bypassed the fix for RoguePlanet (CVE-2026-50656), and The Register counts ShieldCrash as the researcher's 11th Microsoft zero-day. No new CVE is assigned; Microsoft has not confirmed the bypass, awaits independent reproduction (per Cyber Security News), and has given no patch timeline, though Kevin Beaumont confirmed several of the researcher's other recent exploits work as described. The PoC repository reportedly contains C++ project files, a Warden.dll library, and an EICAR test archive, suggesting interaction with Defender's malware-detection workflow. Earlier, on September 7, the researcher released GreenSection, a PoC for an unpatched out-of-bounds write in NVIDIA's Windows user-mode components, which share a global memory section (\BaseNamedObjects\{52813408-3561-4705-820a-2b3b78be92ba}) with full read/write access for all users; the unstable PoC crashes Vulkan/OpenGL applications and may cross user boundaries or compromise dwm.exe, though impact was not fully investigated, and no CVE or patch exists. On September 9 the researcher also published FalconFlank, a CrowdStrike Falcon Sensor privilege-escalation zero-day abusing the high-privilege Microsoft Office suspicious-macro removal feature on fully updated Windows 11 25H2 and Windows Server 2025 with Falcon Phase 3 Optimal Protection; CrowdStrike is investigating and advises disabling that policy (customers remain covered by Cloud Anti-malware for Microsoft Office Files). Prior releases include HardBreacher (Kaspersky Endpoint Security, since patched) and PrettyPrague (Avast, which dumps the SAM database for a SYSTEM shell and may also affect AVG and Norton). No active exploitation of any flaw has been…