CVE-2026-21238 Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
An authorized local attacker can elevate privileges due to improper access control in the Windows Ancillary Function Driver for WinSock.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-21238?
CVE-2026-21238 is a high-severity vulnerability in Microsoft Windows 10 1607, published on 10 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Improper access control in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Weakness: CWE-284
Which versions are affected by CVE-2026-21238?
It affects 13 products.
Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2 and 7 more.
How do I fix CVE-2026-21238?
No fix has been published for CVE-2026-21238 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-21238 being exploited?
There is no known exploitation of CVE-2026-21238 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows 10 1607
- CVE-2026-33824 Microsoft Internet Key Exchange (IKE) Service Extensions Double Free
- CVE-2026-21510 Microsoft Windows Shell Protection Mechanism Failure
- CVE-2026-21513 Microsoft MSHTML Framework Protection Mechanism Failure
- CVE-2023-32049 Microsoft Windows Defender SmartScreen Security Feature Bypass
- CVE-2023-29360 Microsoft Streaming Service Untrusted Pointer Dereference
Sources
Also known as GHSA-pf58-6rw7-w4p4.