Microsoft's May Patch Tuesday update addressed 137 vulnerabilities across its product suite. The release includes a fix for CVE-2026-40361, a critical zero-click remote code execution flaw in Outlook. This vulnerability allows exploitation when a victim reads or previews an email.
Microsoft also unveiled a new AI-driven system codenamed MDASH to autonomously discover software flaws. MDASH identified 16 previously unknown vulnerabilities within Windows. These findings included four critical remote code execution flaws affecting the Windows IPv4 stack and Netlogon. Microsoft patched the AI-discovered vulnerabilities in the May 12 security update.