Chaotic Eclipse released a PoC for ShieldBreak, a Microsoft Defender zero-day that bypasses the CVE-2026-50656 patch and could enable SYSTEM-level code execution. Security researcher Chaotic Eclipse, also known as INFINITE NIGHTMARE, MSNightmare and Nightmare-Eclipse, released a PoC for ShieldBreak, a Microsoft Defender zero-day. The flaw bypasses the patch for CVE-2026-50656 (RoguePlanet), a race condition that […]

The security researcher going by the name Chaotic Eclipse (aka INFINITE NIGHTMARE, MSNightmare, and Nightmare-Eclipse) has released a proof-of-concept (PoC) for a new Microsoft zero-day called ShieldBreak. The vulnerability, rooted in Microsoft Defender for Windows, demonstrates a patch bypass for CVE-2026-50656 (CVSS score: 7.8), otherwise known as RoguePlanet. RoguePlanet has been described

Microsoft has finally released a security update for its Microsoft Malware Protection Engine, which fixes CVE-2026-50656, the Windows Defender local privilege escalation vulnerability triggered by the RoguePlanet exploit. The vulnerability and the fix CVE-2026-50656 is due to improper link resolution before file access, affects Windows 10 and Windows 11, and may allow authenticated attackers to achieve SYSTEM-level privileges on vulnerable machines by launching low-complexity attacks. The flaw’s existence was publicly revealed on June 10, hours … More → The post Microsoft releases fix for RoguePlanet Defender flaw (CVE-2026-50656) appeared first on Help Net Security .

Microsoft fixed RoguePlanet (CVE-2026-50656), a Defender flaw allowing local attackers to gain higher privileges through the Malware Protection Engine. Microsoft released security updates for RoguePlanet, a vulnerability tracked as CVE-2026-50656 (CVSS score of 7.8) affecting the Malware Protection Engine used by Defender. The Microsoft Malware Protection Engine (mpengine.dll) powers Defender’s malware scanning, detection, and removal […]

Microsoft has released security updates for a Defender vulnerability known as RoguePlanet, nearly a month after details of the flaw became public. The vulnerability, tracked as CVE-2026-50656 (CVSS score: 7.8), is a privilege escalation issue in the Microsoft Malware Protection Engine ("mpengine.dll"), which provides scanning, detection, and cleaning capabilities for its antivirus and

Microsoft confirmed the RoguePlanet Defender zero-day (CVE-2026-50656), a privilege escalation flaw, and is developing a security patch. Microsoft has acknowledged the RoguePlanet zero-day affecting Microsoft Defender, tracked as CVE-2026-50656 (CVSS score of 7.8). The vulnerability allows privilege escalation through the Microsoft Malware Protection Engine. The company stated it is aware of the issue and is […]