This vulnerability involves a race condition due to concurrent execution using a shared resource with improper synchronization in the Windows TCP/IP implementation. It is classified as a stack-based buffer overflow (CWE-121) that can be exploited by an authorized local user to gain elevated privileges on the affected system. The vulnerability affects Windows 10 Version 1607, specifically build 10.0.14393.0. Microsoft has published an official fix to remediate this issue.

Successful exploitation of this vulnerability could allow an authorized local attacker to elevate their privileges, potentially gaining higher-level access to the system. The CVSS v3.1 base score is 7.8, indicating high severity with high impact on confidentiality, integrity, and availability.

An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 10 Version 1607 (build 10.0.14393.0) as soon as possible. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40399 for detailed patching instructions.