CVE-2026-21238
HIGHCVSS 7.8/10EPSS 3.23%
Last modified
CVE-2026-21238 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. Improper access control in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.. EPSS estimates a 3.23% chance of exploitation in the next 30 days.
Description
Improper access control in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 10 1607 | < 10.0.14393.8868 |
| Microsoft | Windows 10 1809 | < 10.0.17763.8389 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.6937 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.6937 |
| Microsoft | Windows 11 23h2 | < 10.0.22631.6649 |
| Microsoft | Windows 11 24h2 | < 10.0.26100.7781 |
| Microsoft | Windows 11 25h2 | < 10.0.26200.7781 |
| Microsoft | Windows Server 2012 | All versions |
| Microsoft | Windows Server 2012 | r2 |
| Microsoft | Windows Server 2016 | < 10.0.14393.8868 |
| 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
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-21238?
Improper access control in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
How severe is CVE-2026-21238?
CVE-2026-21238 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 3.23% probability of exploitation in the next 30 days.
How do I fix CVE-2026-21238?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
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Are you affected by CVE-2026-21238?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST