ShieldBreak Bypasses Microsoft Defender Patch, Leaving Users Vulnerable

A newly discovered vulnerability in Microsoft Defender called ShieldBreak has been found to bypass the patch for an earlier flaw. The issue, identified as CVE-2026-69414, is an elevation of privilege (EoP) vulnerability in the Malware Protection Engine.

Microsoft acknowledged a similar vulnerability, RoguePlanet, on June 16 and patched it on July 8. However, the fix did not eliminate the weakness at its root, allowing a researcher to find a different route to reach the same end result with ShieldBreak.

ShieldBreak requires Microsoft Defender to be enabled in order to work and appears to be a local privilege escalation issue. Disabling Defender seems to stop this specific chain from working, but that's not recommended as it removes an important layer of protection.