Researcher Drops New Microsoft Defender PoC Showing ShieldBreak Patch Can Be Bypassed

Researcher Drops New Microsoft Defender PoC Showing ShieldBreak Patch Can Be Bypassed Ravie LakshmananSep 09, 2026Vulnerability / Endpoint Security The security researcher known as Chaotic Eclipse has dropped a proof-of-concept (PoC) for yet another zero-day in Microsoft Defender. The vulnerability, codenamed ShieldCrash, is assessed to be a patch bypass for CVE-2026-69414 (CVSS score: 7.8), also called ShieldBreak, which the researcher reported last month. "Microsoft has failed to properly patch ShieldBreak CVE-2026-69414," Chaotic Eclipse said. "Under specific conditions it is still possible to trigger the exact same problem that was caused by ShieldBreak. While Microsoft fixed several things to prevent re-exploiting the issue, they missed a spot where ShieldBreak can still be exploited." The PoC demonstrates an arbitrary file read as…