CVE-2026-20831 | Microsoft Windows up to Server 2025 Ancillary Function Driver for WinSock toctou

January 13, 2026 Yanac

A vulnerability was found in Microsoft Windows. It has been classified as critical. The impacted element is an unknown function of the component Ancillary Function Driver for WinSock. This manipulation causes time-of-check time-of-use.

This vulnerability is registered as CVE-2026-20831. The attack needs to be launched locally. No exploit is available.

Applying a patch is the recommended action to fix this issue.VulDB Recent EntriesRead More