ShieldBreak bypasses Microsoft’s patch for earlier Defender flaw

A new vulnerability dubbed ShieldBreak (CVE-2026-69414) has been discovered in Microsoft Defender, which bypasses a previous patch for a similar flaw called RoguePlanet. This elevation of privilege vulnerability requires initial access to a machine and is dependent on Microsoft Defender being active. Microsoft has acknowledged the issue and is working on a fix, advising users to maintain security updates and exercise caution with untrusted code.