CHAOTIC Eclipse, a security researcher, has released a proof-of-concept (PoC) for a new zero-day vulnerability named ShieldBreak, which bypasses a Microsoft Defender patch for CVE-2026-50656. This flaw allows attackers to achieve SYSTEM-level code execution on Windows systems, risking unauthorized actions. Microsoft had previously identified this issue and claimed to provide a patch, but the PoC demonstrates a complete bypass of the fix.
The researcher asserts the PoC has a 100% success rate on Windows 11 and 2025 Server, with Windows 10 also being vulnerable but unsupported by the PoC. Additionally, Chaotic Eclipse has a history of disclosing various Windows vulnerabilities and has criticized Microsoft for their handling of these disclosures.