CVE-2026-21236 | Microsoft Windows up to Server 2025 Ancillary Function Driver for WinSock heap-based overflow
A vulnerability was found in Microsoft Windows. It has been rated as critical. This issue affects some unknown processing of the component Ancillary Function Driver for WinSock. Performing a manipulation results in heap-based buffer overflow.
This vulnerability is identified as CVE-2026-21236. The attack is only possible with local access. There is not any exploit available.
Applying a patch is the recommended action to fix this issue.