A zero-day vulnerability in Microsoft Defender, dubbed RoguePlanet, enables attackers to escalate privileges to SYSTEM level on affected systems. The flaw was disclosed publicly shortly after Microsoft addressed two other Defender vulnerabilities in their June 2026 security updates. This represents a critical gap in endpoint protection that could allow threat actors to gain maximum control over compromised machines.

Why it matters in Western Canada: Organizations across Western Canada—particularly government agencies, post-secondary institutions, healthcare facilities, and financial services—rely heavily on Microsoft Defender for endpoint protection. A SYSTEM-level privilege escalation in this core security tool poses an immediate risk to institutional networks and sensitive data.

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Summary generated from the original advisory. Read the full source: bleepingcomputer