Microsoft 365 threat report

Researcher Nightmare Eclipse publicly released RoguePlanet, a proof-of-concept exploit for a previously undisclosed race condition (TOCTOU) vulnerability in Microsoft Windows Defender on June 10, 2026. The exploit allows local privilege escalation to SYSTEM level and has been confirmed working on fully patched Windows 10, Windows 11, and Windows Server systems. This zero-day disclosure came hours after Microsoft's record Patch Tuesday release and represents the latest in a series of Defender-targeting exploits from the same researcher since April 2026.

• Record Microsoft Patch Tuesday, fresh zero-day - Help Net Securi(opens in a new tab)
• New Windows Defender 0-Day Exploit “RoguePlanet” Grants SYSTEM A(opens in a new tab)