Microsoft

Overview Attribute CVE-2026-41091 CVE-2026-45498 Type Local Privilege Escalation Denial of Service Component Malware Protection Engine Antimalware Platform Affected Engine ≤ 1.1.26030.3008 Platform ≤ 4.18.26030.3011 CWE CWE-59 (Link Following) — Impact Standard user → SYSTEM Defender disabled / system unresponsive Exploit ✅ Active in the wild ✅ Active in the wild Patch Engine 1.1.26040.8 Platform 4.18.26040.7 CISA KEV ✅ Added 2026-05-20 ✅ Added 2026-05-20 FCEB Deadline June 3, 2026 June 3, 2026 Microsoft has started rolling out patches for two actively exploited zero-day vulnerabilities in Microsoft Defender. Both were added to CISA’s Known Exploited Vulnerabilities (KEV) catalog on May 20, with federal agencies ordered to patch within two weeks. ...

This week proves that old vulnerabilities never die — they just wait for someone to look. NGINX Rift is an 18-year-old heap buffer overflow in the rewrite module that delivers RCE, discovered by an autonomous code analysis system. Exim’s Dead.Letter achieves unauthenticated remote code execution through a use-after-free triggered by a single stray byte in GnuTLS. Palo Alto ships a second PAN-OS RCE in two weeks — this time in IKEv2 processing. Microsoft’s May Patch Tuesday delivers 137 CVEs including critical Windows Netlogon and DNS overflows. And GreenPlasma (SB2026051378) continues Chaotic Eclipse’s disclosure campaign with a ctfmon.exe section hijack that escalates standard users to SYSTEM on Windows 11. Meanwhile in the lab, Pupy C2 completed its Python 3 migration, Nextcloud got a major version upgrade, Tailscale funnel replaced port forwarding for Plex remote access, and Max’s weekly audit found critical firewall gaps across two homelab hosts. ...

Microsoft dropped the CVE-2025-53770 advisory on a Saturday. For organizations without 24/7 Security Operations Centers, that timing was devastating. ToolShell represents everything that can go wrong in vulnerability disclosure: critical severity, unauthenticated exploitation, wide deployment, and a gap between disclosure and patch availability. By the time many teams saw the advisory, attackers were already inside. Understanding the Vulnerability Technical Details CVE: CVE-2025-53770 CVSS: Critical (9.8+) Type: Unauthenticated Remote Code Execution Affected: Microsoft SharePoint Server (multiple versions) Exploitation: Began within days of disclosure The Attack Path SharePoint is often deployed in perimeter-exposed configurations, making it reachable from the internet. Even when internal-facing, SharePoint’s tight integration with Active Directory means compromise leads directly to: ...