Vulnerability Management Microsoft releases patch for Defender zero-day vulnerability RoguePlanet July 9, 2026 Share By SC Staff (Adobe Stock) Bleeping Computer reports that Microsoft has released a security patch to address a zero-day vulnerability in Microsoft Defender, known as "RoguePlanet," which was disclosed after the June 2026 Patch Tuesday. The vulnerability, tracked as CVE-2026-50656, was revealed by a security researcher using the handle "Nightmare Eclipse." The researcher also shared a proof-of-concept exploit, claiming that Microsoft had previously removed their exploit repositories from platforms like GitHub and GitLab. According to Nightmare Eclipse, RoguePlanet affects fully patched Windows 10 and Windows 11 devices. It allows attackers to spawn a command prompt with SYSTEM privileges through a race condition within Microsoft Defender. Microsoft confirmed it was working on a patch and has since released an update to the Microsoft Malware Protection Engine, version 1.1.26060.3008, to address the flaw. This incident follows a series of other zero-day disclosures by Nightmare Eclipse, including vulnerabilities affecting BlueHammer, RedSun, GreenPlasma, MiniPlasma, YellowKey, and UnDefend. Microsoft has previously issued warnings of legal action against individuals engaging in activities that cause harm to customers, leading to speculation that these warnings were directed at the researcher. Source: Bleeping Computer SC Staff Related Vulnerability Management CISA adds ColdFusion, Langflow, and Joomla bugs to known exploited vulnerabilities list Steve Zurier July 8, 2026 Three of the four flaws added to CISA's KEV list were critical. Vulnerability Management ‘Bad Epoll’ vulnerability allows root access on Linux and Android SC Staff July 6, 2026 The Bad Epoll flaw resides within the epoll subsystem of the Linux kernel, a fundamental component for managing network connections and file events. Vulnerability Management Opera GX browser vulnerability could allow data theft and DoS attacks SC Staff July 6, 2026 The vulnerability, found by security researcher zhero_web_security, allows for a zero-click cross-site leak (XS-Leak) by exploiting the automatic installation of GX Mods. Related Events Cybercast Why Mythos is the cybersecurity crisis we need Wed Jul 22 Get daily email updates SC Media's daily must-read of the most current and pressing daily news Business Email By clicking the Subscribe button below, you agree to SC Media Terms of Use and Privacy Policy . Subscribe Related Terms Bug Buffer Overflow Disassembly You can skip this ad in 5 seconds