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7.3 High

CVE-2026-21247 Improper input validation in Windows Hyper-V allows an authorized attacker to execute code locally

Description

Improper input validation in Windows Hyper-V allows an authorized attacker to execute code locally.

Affected products and versions

Product Affected versions Fixed in
Windows 11 version 26H1 10.0 10.0.28000.0 → < 10.0.28000.1575 10.0.28000.1575
Windows 10 Version 1809 10.0 10.0.17763.0 → < 10.0.17763.8389 10.0.17763.8389
Windows Server 2019 10.0 10.0.17763.0 → < 10.0.17763.8389 10.0.17763.8389
Windows Server 2019 (Server Core installation) 10.0 10.0.17763.0 → < 10.0.17763.8389 10.0.17763.8389
Windows Server 2022 10.0 10.0.20348.0 → < 10.0.20348.4773 10.0.20348.4773
Windows 10 Version 21H2 10.0 10.0.19044.0 → < 10.0.19044.6937 10.0.19044.6937
Windows 10 Version 22H2 10.0 10.0.19045.0 → < 10.0.19045.6937 10.0.19045.6937
Windows Server 2025 (Server Core installation) 10.0 10.0.26100.0 → < 10.0.26100.32370 10.0.26100.32370
Windows 11 Version 25H2 10.0 10.0.26200.0 → < 10.0.26200.7840 10.0.26200.7840
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Product Affected versions Fixed in
Windows 11 version 22H3 10.0 10.0.22631.0 → < 10.0.22631.6649 10.0.22631.6649
Windows 11 Version 23H2 10.0 10.0.22631.0 → < 10.0.22631.6649 10.0.22631.6649
Windows Server 2022, 23H2 Edition (Server Core installation) 10.0 10.0.25398.0 → < 10.0.25398.2149 10.0.25398.2149
Windows 11 Version 24H2 10.0 10.0.26100.0 → < 10.0.26100.7840 10.0.26100.7840
Windows Server 2025 10.0 10.0.26100.0 → < 10.0.26100.32370 10.0.26100.32370
Windows 10 Version 1607 10.0 10.0.14393.0 → < 10.0.14393.8868 10.0.14393.8868
Windows Server 2016 10.0 10.0.14393.0 → < 10.0.14393.8868 10.0.14393.8868
Windows Server 2016 (Server Core installation) 10.0 10.0.14393.0 → < 10.0.14393.8868 10.0.14393.8868

Other CVEs of Windows 11 version 26H1

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