Vulnerability · NVD
CVE-2026-21255
HIGH 8.8
Vendor bulletin scale — NVD CVSS pending
Windows Hyper-V Security Feature Bypass Vulnerability
EPSS
0.36%
exploit very unlikely
percentile 28.4%
OS versions that fix this CVE
This CVE is resolved by the following OS security releases. Update the OS to at least the listed version.
- Windows Server 2025 Fixed in 10.0.26100.32370
- Windows Server 2022 (Server Core installation) Fixed in 10.0.20348.4773
- Windows Server 2022 Fixed in 10.0.25398.2149
- Windows Server 2019 Fixed in 10.0.17763.8389
- Windows Server 2016 Fixed in 10.0.14393.8868
- Windows 11 26H1 · 2026-H1 Fixed in 10.0.28000.1575
- Windows 11 25H2 · 2025-H2 Fixed in 10.0.26200.7840
- Windows 11 24H2 · 2024-H2 Fixed in 10.0.26100.7840
- Windows 11 23H2 · 2023-H2 Fixed in 10.0.22631.6649
- Windows 10 22H2 · 2022-H2 Fixed in 10.0.19045.6937
- Windows 10 21H2 · 2021-H2 Fixed in 10.0.19044.6937
- Windows 10 1809 · 2018-09 Fixed in 10.0.17763.8389
- Windows 10 1607 · 2016-07 Fixed in 10.0.14393.8868