Microsoft patches RoguePlanet Defender zero-day vulnerability

Summary

Microsoft has released a security patch for a zero-day vulnerability in Microsoft Defender, dubbed "RoguePlanet." This vulnerability was disclosed after the June 2026 Patch Tuesday updates.

IFF Assessment

FOE

The discovery and exploitation of a zero-day vulnerability in a widely used security product like Microsoft Defender represents a significant risk to defenders.

Severity

9.8 Critical (AI Estimated)

The CVSS score is estimated to be high (9.8) due to the potential for remote code execution with high privileges on protected systems, as it's a zero-day in a critical security component like Microsoft Defender.

Defender Context

Defenders should prioritize patching this vulnerability immediately to prevent potential exploitation. Zero-day vulnerabilities in endpoint detection and response (EDR) solutions are particularly dangerous, as they can be used to bypass security measures and gain deep access to systems.

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