CVE-2026-69414 ShieldBreak Zero-Day: Elevation of Privilege in Microsoft Malware Protection Engine
A zero-day elevation-of-privilege vulnerability, CVE-2026-69414, has been discovered in the Microsoft Malware Protection Engine used by Microsoft Defender. This vulnerability allows a low-privilege local attacker to escalate to SYSTEM. A public proof-of-concept (PoC) was released on August 12, 2026, and Microsoft assigned the CVE on August 14, 2026. No patch is currently available, and CISA BOD 26-04 requires mitigation within 14 days. The vulnerability has been actively exploited, and organizations are advised to implement immediate mitigations.