Chaotic Eclipse Unveils ShieldCrash, A PoC For Microsoft Defender Zero-Day Vulnerability

Chaotic Eclipse has released ShieldCrash, a proof-of-concept (PoC) exploit for a Microsoft Defender Zero-Day vulnerability. The researcher claims that Microsoft has not fully fixed the ShieldBreak vulnerability (CVE-2026-69414). Although Microsoft closed several ways to exploit the flaw, Chaotic Eclipse says there is still a specific condition that allows the same attack.

The PoC exploits trigger an arbitrary file read as SYSTEM, which is the highest level of access on Windows. This means that ShieldCrash can potentially allow attackers to gain elevated privileges and access sensitive files.

Chaotic Eclipse notes that all supported Windows versions remain vulnerable, even after the September 2026 security updates. The researcher warns that Microsoft's patch does not completely block ShieldBreak, making it possible for attackers to exploit this vulnerability.