CVE-2026-21248
High
Description
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
SeverityHigh
CVSS7.3
Exploit probability—
Product
Microsoft Windows
PublishedFeb 10, 2026
First seenFeb 10, 2026
Weakness typeCWE-122CWE-122
How to fix
Update
- microsoft windows_10_160710.0.14393.8868 or later
- microsoft windows_10_180910.0.17763.8389 or later
- microsoft windows_10_21h210.0.19044.6937 or later
- microsoft windows_10_22h210.0.19045.6937 or later
- microsoft windows_11_23h210.0.22631.6649 or later
- microsoft windows_11_24h210.0.26100.7781 or later
- microsoft windows_11_25h210.0.26200.7781 or later
- microsoft windows_server_201610.0.14393.8868 or later
- microsoft windows_server_201910.0.17763.8389 or later
- microsoft windows_server_202210.0.20348.4711 or later
- microsoft windows_server_2022_23h210.0.25398.2149 or later
- microsoft windows_server_202510.0.26100.32313 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| microsoft windows_10_1607 | v < 10.0.14393.8868 | 10.0.14393.8868 |
| microsoft windows_10_1809 | v < 10.0.17763.8389 | 10.0.17763.8389 |
| microsoft windows_10_21h2 | v < 10.0.19044.6937 | 10.0.19044.6937 |
| microsoft windows_10_22h2 | v < 10.0.19045.6937 | 10.0.19045.6937 |
| microsoft windows_11_23h2 | v < 10.0.22631.6649 | 10.0.22631.6649 |
| microsoft windows_11_24h2 | v < 10.0.26100.7781 | 10.0.26100.7781 |
| microsoft windows_11_25h2 | v < 10.0.26200.7781 | 10.0.26200.7781 |
| microsoft windows_server_2016 | v < 10.0.14393.8868 | 10.0.14393.8868 |
| microsoft windows_server_2019 | v < 10.0.17763.8389 | 10.0.17763.8389 |
| microsoft windows_server_2022 | v < 10.0.20348.4711 | 10.0.20348.4711 |
| microsoft windows_server_2022_23h2 | v < 10.0.25398.2149 | 10.0.25398.2149 |
| microsoft windows_server_2025 | v < 10.0.26100.32313 | 10.0.26100.32313 |
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