CVE-2026-70342: CWE-416: Use After Free in Microsoft Windows 10 Version 1607

This vulnerability (CVE-2026-70342) involves a use-after-free condition in the Windows Ancillary Function Driver for WinSock. It affects various builds of Windows 10, including Version 1607 and later builds up to specific patched versions. Exploitation can lead to elevation of privileges by an unauthorized attacker remotely over a network. The CVSS 3.1 base score is 8.1, indicating high severity with network attack vector, high impact on confidentiality, integrity, and availability, and requiring no user interaction but high attack complexity. Microsoft has released an official fix for this vulnerability.

Successful exploitation allows an unauthorized attacker to elevate privileges remotely over a network, potentially gaining high-level access to the affected system. This could compromise system confidentiality, integrity, and availability.

An official fix is available from Microsoft. Users and administrators should apply the security updates provided by Microsoft for the affected Windows 10 versions as detailed in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70342.