high8.8
CVE-2026-21255
Improper access control in Windows Hyper-V allows an authorized attacker to bypass a security feature locally.
Impact
Improper access control in Windows Hyper-V allows an authorized attacker to bypass a security feature locally.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Microsoft | Windows 10 1607 | before 10.0.14393.8868 |
| Microsoft | Windows 10 1809 | before 10.0.17763.8389 |
| Microsoft | Windows 10 21h2 | before 10.0.19044.6937 |
| Microsoft | Windows 10 22h2 | before 10.0.19045.6937 |
| Microsoft | Windows 11 23h2 | before 10.0.22631.6649 |
| Microsoft | Windows 11 24h2 | before 10.0.26100.7781 |
| Microsoft | Windows 11 25h2 | before 10.0.26200.7781 |
| Microsoft | Windows Server 2016 | before 10.0.14393.8868 |
| Microsoft | Windows Server 2019 | before 10.0.17763.8389 |
| Microsoft | Windows Server 2022 | before 10.0.20348.4711 |
| Microsoft | Windows Server 2022 23h2 | before 10.0.25398.2149 |
| Microsoft | Windows Server 2025 | before 10.0.26100.32313 |