CVE-2026-40402
Critical
Description
Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.
SeverityCritical
CVSS9.3
Exploit probability—
Product
Microsoft Windows
PublishedMay 12, 2026
First seenMay 12, 2026
Weakness typeCWE-416Use after free
How to fix
Update
- microsoft windows_11_23h210.0.22631.7079 or later
- microsoft windows_server_202210.0.20348.5074 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| microsoft windows_11_23h2 | v < 10.0.22631.7079 | 10.0.22631.7079 |
| microsoft windows_server_2022 | v < 10.0.20348.5074 | 10.0.20348.5074 |
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