CVE-2026-20921
No fix known EPSS 1%CVSS 7.5
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.
Products: Microsoft Windows 10 Version 1607, Microsoft Windows 10 Version 1809, Microsoft Windows 10 Version 21H2, Microsoft Windows 10 Version 22H2, Microsoft Windows 11 Version 23H2, Microsoft Windows 11 Version 24H2, Microsoft Windows 11 Version 25H2, Microsoft Windows Server 2008 R2 Service Pack 1, Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation), Microsoft Windows Server 2008 Service Pack 2, Microsoft Windows Server 2008 Service Pack 2 (Server Core installation), Microsoft Windows Server 2012, Microsoft Windows Server 2012 (Server Core installation), Microsoft Windows Server 2012 R2, Microsoft Windows Server 2012 R2 (Server Core installation), Microsoft Windows Server 2016, Microsoft Windows Server 2016 (Server Core installation), Microsoft Windows Server 2019, Microsoft Windows Server 2019 (Server Core installation), Microsoft Windows Server 2022, Microsoft Windows Server 2022, 23H2 Edition (Server Core installation), Microsoft Windows Server 2025, Microsoft Windows Server 2025 (Server Core installation)