cve-2026-40413

CVE-2026-40413 is a Windows TCP/IP denial-of-service vulnerability disclosed by Microsoft in its May 12, 2026 Patch Tuesday release. Rated Important with a CVSS base score of 7.4, the vulnerability affects a core networking component that every connected Windows system relies on. At the time of disclosure, there was no known public exploitation or disclosure. For IT administrators, the recommended response is disciplined patch prioritization, particularly for exposed Windows servers, VPN-adjacent systems, and machines where availability is critical. While not a code-execution bug, CVE-2026-40413 requires attention because it targets a fundamental part of Windows networking.