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7.8 High

CVE-2026-20831 Time-of-check time-of-use (toctou) race condition in Windows Ancillary Function Driver for WinSock allows an…

Description

Time-of-check time-of-use (toctou) race condition in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Affected products and versions

Product Affected versions Fixed in
Windows 10 Version 1809 10.0 10.0.17763.0 → < 10.0.17763.8276 10.0.17763.8276
Windows Server 2019 10.0 10.0.17763.0 → < 10.0.17763.8276 10.0.17763.8276
Windows Server 2019 (Server Core installation) 10.0 10.0.17763.0 → < 10.0.17763.8276 10.0.17763.8276
Windows Server 2022 10.0 10.0.20348.0 → < 10.0.20348.4648 10.0.20348.4648
Windows 10 Version 21H2 10.0 10.0.19044.0 → < 10.0.19044.6809 10.0.19044.6809
Windows 10 Version 22H2 10.0 10.0.19045.0 → < 10.0.19045.6809 10.0.19045.6809
Windows Server 2025 (Server Core installation) 10.0 10.0.26100.0 → < 10.0.26100.32230 10.0.26100.32230
Windows 11 Version 25H2 10.0 10.0.26200.0 → < 10.0.26200.7623 10.0.26200.7623
Windows 11 version 22H3 10.0 10.0.22631.0 → < 10.0.22631.6491 10.0.22631.6491
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Product Affected versions Fixed in
Windows 11 Version 23H2 10.0 10.0.22631.0 → < 10.0.22631.6491 10.0.22631.6491
Windows Server 2022, 23H2 Edition (Server Core installation) 10.0 10.0.25398.0 → < 10.0.25398.2092 10.0.25398.2092
Windows 11 Version 24H2 10.0 10.0.26100.0 → < 10.0.26100.7623 10.0.26100.7623
Windows Server 2025 10.0 10.0.26100.0 → < 10.0.26100.32230 10.0.26100.32230
Windows 10 Version 1607 10.0 10.0.14393.0 → < 10.0.14393.8783 10.0.14393.8783
Windows Server 2016 10.0 10.0.14393.0 → < 10.0.14393.8783 10.0.14393.8783
Windows Server 2016 (Server Core installation) 10.0 10.0.14393.0 → < 10.0.14393.8783 10.0.14393.8783
Windows Server 2008 Service Pack 2 6.0 6.0.6003.0 → < 6.0.6003.23717 6.0.6003.23717
Windows Server 2008 Service Pack 2 (Server Core installation) 6.0 6.0.6003.0 → < 6.0.6003.23717 6.0.6003.23717
Windows Server 2008 R2 Service Pack 1 6.1 6.1.7601.0 → < 6.1.7601.28117 6.1.7601.28117
Windows Server 2008 R2 Service Pack 1 (Server Core installation) 6.1 6.1.7601.0 → < 6.1.7601.28117 6.1.7601.28117
Windows Server 2012 6.2 6.2.9200.0 → < 6.2.9200.25868 6.2.9200.25868
Windows Server 2012 (Server Core installation) 6.2 6.2.9200.0 → < 6.2.9200.25868 6.2.9200.25868
Windows Server 2012 R2 6.3 6.3.9600.0 → < 6.3.9600.22968 6.3.9600.22968
Windows Server 2012 R2 (Server Core installation) 6.3 6.3.9600.0 → < 6.3.9600.22968 6.3.9600.22968

References

Timeline

  1. Published
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