high7.8
CVE-2026-21240
Time-of-check time-of-use (toctou) race condition in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.
Impact
Time-of-check time-of-use (toctou) race condition in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| 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 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 |