Elevation of Privilege Vulnerability in Windows Ancillary Function Driver for WinSock
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?

A use-after-free vulnerability exists in the Windows Ancillary Function Driver for WinSock that allows an attacker with valid access to elevate their privileges. This flaw could enable the attacker to gain additional control over the affected system, leading to potential unauthorized access or execution of arbitrary code.

Affected Version(s)

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

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
High
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.