ShieldBreak: New Windows Zero-Day Bypasses Microsoft’s RoguePlanet Patch
Researcher Chaotic Eclipse published a PoC bypassing Microsoft's CVE-2026-50656 Defender patch, enabling SYSTEM-level code execution on fully patched Windows systems.
Security researcher Chaotic Eclipse released a proof-of-concept for ShieldBreak, a Microsoft Defender zero-day that fully bypasses the patch for CVE-2026-50656 (RoguePlanet), a race condition in the Malware Protection Engine (mpengine.dll) allowing SYSTEM-level code execution. The PoC was tested on Windows 11 25H2 and Windows Server 2025 with a 100% success rate, and Windows 10 is also vulnerable though not supported by the PoC; the flaw may also leak 8 bytes of memory. Microsoft's MSRC had criticized the researcher's repeated uncoordinated disclosures, including YellowKey (BitLocker bypass), GreenPlasma, and LegacyHive (User Profile Service LPE).
ownCloud Flaw Exploited to Steal Nuclear Records From Philippine Research Body
A Chinese-speaking actor exploited ownCloud CVE-2023-49105 to steal 176 nuclear research files from Philippine organizations, prompting CISA to add the flaw to KEV.
CISA added CVE-2023-49105 (CVSS 9.8), an ownCloud WebDAV API authentication bypass fixed in version 10.13.1, to the KEV catalog after Hunt.io found an open directory hosting custom Python exploit scripts and tools including Sliver, Metasploit, and Mettle. The actor downloaded 176 files (~372 MB) from a Philippine nuclear research body, including nuclear-material account records, 2023-2028 strategic plans, BitLocker keys, and a KeePass database; a second intrusion exploited LiteSpeed Cache CVE-2024-28000 at a shipbuilding firm serving the Philippine Navy, with XML-RPC brute-force and an EtherHiding/ClickFix component. FCEB agencies must patch by August 30, 2026. CISA also added Linux Kernel CVE-2026-53362 and Artifactory CVE-2026-66384 after OpenAI said its AI agents exploited them against internal infrastructure.