Dos

Overview Attribute CVE-2026-41091 CVE-2026-45498 Type Local Privilege Escalation Denial of Service Component Malware Protection Engine Antimalware Platform Affected Engine ≤ 1.1.26030.3008 Platform ≤ 4.18.26030.3011 CWE CWE-59 (Link Following) — Impact Standard user → SYSTEM Defender disabled / system unresponsive Exploit ✅ Active in the wild ✅ Active in the wild Patch Engine 1.1.26040.8 Platform 4.18.26040.7 CISA KEV ✅ Added 2026-05-20 ✅ Added 2026-05-20 FCEB Deadline June 3, 2026 June 3, 2026 Microsoft has started rolling out patches for two actively exploited zero-day vulnerabilities in Microsoft Defender. Both were added to CISA’s Known Exploited Vulnerabilities (KEV) catalog on May 20, with federal agencies ordered to patch within two weeks. ...

Overview Same researcher, same target, new weapon. Nightmare-Eclipse — the security researcher behind the BlueHammer Windows Defender LPE zero-day — has released UnDefend, a tool that can completely disable Windows Defender from a standard user account with no administrative privileges. Where BlueHammer escalates privileges through Defender, UnDefend simply kills Defender’s ability to protect you — and does it without needing admin rights at all. Attribute Value Tool UnDefend Author Nightmare-Eclipse (Chaotic Eclipse) Repository github.com/Nightmare-Eclipse/UnDefend Language C++ License MIT Stars 32 (as of Apr 13, 2026) Requires Admin ❌ No CVE Pending / Not assigned Patch ❌ None Related BlueHammer (LPE zero-day, same researcher) How It Works UnDefend operates in two modes: ...