A newly discovered zero-day exploit, dubbed "RoguePlanet", has been found in Microsoft Defender, allowing attackers to gain SYSTEM privileges. This vulnerability was disclosed just hours after Microsoft addressed two other flaws in their June 2026 Patch Tuesday updates. The "RoguePlanet" exploit enables malicious actors to escalate privileges, posing a significant threat to system security. Microsoft has yet to release a patch for this vulnerability, leaving users exposed1. The rapid disclosure of this zero-day exploit underscores the need for prompt action, as the window for patching is already closing. This exploit has significant implications for system administrators, who must assess their exposure immediately to prevent potential attacks. The fact that this vulnerability was discovered so soon after the latest patch updates highlights the ongoing cat-and-mouse game between security researchers and attackers, making it crucial for practitioners to stay vigilant and prioritize patch management.