Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
CVE-2026-42911

7HIGH

Key Information:

Vendor: Microsoft
Status: Windows 10 Version 1607; Windows 10 Version 1809; Windows 10 Version 21h2; Windows 10 Version 22h2
Vendor: CVE Published:; 9 June 2026

What is CVE-2026-42911?

Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Windows 10 Version 1607 32-bit Systems 10.0.14393.0 < 10.0.14393.9234

Windows 10 Version 1809 32-bit Systems 10.0.17763.0 < 10.0.17763.8880

Windows 10 Version 21H2 32-bit Systems 10.0.19044.0 < 10.0.19044.7417

Score:

Severity:

HIGH

Confidentiality:

High

Integrity:

High

Availability:

High

Attack Vector:

Local

Attack Complexity:

High

Privileges Required:

Low

User Interaction:

None

Scope:

Unchanged

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CVE-2026-42911 Data