Signal is active with 1 mentions in latest observed window
Recommended action window: Monitor and triage in normal cycle
NVD description
Time-of-check time-of-use (toctou) race condition in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.
Priority
LOW
Exploitation
NONE
PoC
NONE
Patch
NONE
Momentum
NONE
If you run products in this scope, you should treat this CVE as relevant to your environment.
CVE-2026-21240 Time-of-check time-of-use (toctou) race condition in Windows HTTP.sys allows an authorized attacker to elevate privileges locally. https://www.cve.org/CVERecord?id=CVE-2026-21240
Post summary
CVE-2026-21240 is a race condition in Windows HTTP.sys that enables authorized local attackers to elevate privileges; the announcement focuses solely on the vulnerability description.
18 of 18 entries
| Part | Vendor | Product | Version | Target SW | Target HW |
|---|---|---|---|---|---|
| OS | microsoft | windows_10_1809 | - | - | x64 |
| OS | microsoft | windows_10_1809 | - | - | x86 |
| OS | microsoft | windows_10_21h2 | - | - | arm64 |
| OS | microsoft | windows_10_21h2 | - | - | x64 |
| OS | microsoft | windows_10_21h2 | - | - | x86 |
| OS | microsoft | windows_10_22h2 | - | - | arm64 |
| OS | microsoft | windows_10_22h2 | - | - | x64 |
| OS | microsoft | windows_10_22h2 | - | - | x86 |
| OS | microsoft | windows_11_23h2 | - | - | arm64 |
| OS | microsoft | windows_11_23h2 | - | - | x64 |
| OS | microsoft | windows_11_24h2 | - | - | arm64 |
| OS | microsoft | windows_11_24h2 | - | - | x64 |
| OS | microsoft | windows_11_25h2 | - | - | arm64 |
| OS | microsoft | windows_11_25h2 | - | - | x64 |
| OS | microsoft | windows_server_2019 | - | - | - |
| OS | microsoft | windows_server_2022 | - | - | - |
| OS | microsoft | windows_server_2022_23h2 | - | - | - |
| OS | microsoft | windows_server_2025 | - | - | - |