CVE-2021-26879: Microsoft Windows 10

High severity, CVSS 7.5. EPSS: 3.8% chance of exploitation in the next 30 days.

Windows Network Address Translation (NAT) Denial of Service Vulnerability

Affected products

• Microsoft Windows 10: affected versions not specified; version 20h2 only; version 1607 only; version 1803 only; version 1809 only; version 1909 only; …
• Microsoft Windows 8.1: affected versions not specified
• Microsoft Windows Server 2012: version r2 only
• Microsoft Windows Server 2016: affected versions not specified; version 20h2 only; version 1909 only; version 2004 only
• Microsoft Windows Server 2019: affected versions not specified

Published 2021-03-11. Last modified 2026-08-19.