CVE-2026-21240
HIGH EPSS 18.3%
Published Feb 10, 20264mo ago · Modified Jun 17, 20261w ago
7.0 CVSS 3.1
Published Feb 10, 2026 4mo ago
Last Modified Jun 17, 2026 1w ago
Description
Time-of-check time-of-use (toctou) race condition in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Attack Vector Local
Attack Complexity High
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High
Threat Intelligence
EPSS Exploit Probability
18.3% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-367
Affected Products 18
| Vendor | Product | Version | Range |
|---|---|---|---|
| microsoft | windows_10_1809 | * | <10.0.17763.8389 |
| microsoft | windows_10_1809 | * | <10.0.17763.8389 |
| microsoft | windows_10_21h2 | * | <10.0.19044.6937 |
| microsoft | windows_10_21h2 | * | <10.0.19044.6937 |
| microsoft | windows_10_21h2 | * | <10.0.19044.6937 |
| microsoft | windows_10_22h2 | * | <10.0.19045.6937 |
| microsoft | windows_10_22h2 | * | <10.0.19045.6937 |
| microsoft | windows_10_22h2 | * | <10.0.19045.6937 |
| microsoft | windows_11_23h2 | * | <10.0.22631.6649 |
| microsoft | windows_11_23h2 | * | <10.0.22631.6649 |
| microsoft | windows_11_24h2 | * | <10.0.26100.7781 |
| microsoft | windows_11_24h2 | * | <10.0.26100.7781 |
| microsoft | windows_11_25h2 | * | <10.0.26200.7781 |
| microsoft | windows_11_25h2 | * | <10.0.26200.7781 |
| microsoft | windows_server_2019 | * | <10.0.17763.8389 |
| microsoft | windows_server_2022 | * | <10.0.20348.4711 |
| microsoft | windows_server_2022_23h2 | * | <10.0.25398.2149 |
| microsoft | windows_server_2025 | * | <10.0.26100.32313 |
References 1
- msrc.microsoft.com https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21240
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.