An integer underflow within the Windows NT OS Kernel enables a local attacker with authorized access to elevate privileges. The flaw can cause a wraparound condition that potentially leads to privilege escalation by granting the attacker higher privileges. The impact is confined to operating within the local system context and does not automatically provide network or remote execution capabilities.

The vulnerability affects Microsoft Windows 10 versions 1607, 1809, 21H2, and 22H2, Microsoft Windows 11 versions 23H2, 24H2, 25H2, and 26H1 (including both x64 and arm64 builds), and Microsoft Windows Server editions 2012, 2012 R2, 2016, 2019, 2022, and 2025 (full and Server Core installations).

With a CVSS score of 7.8, the flaw is classified as high severity. The EPSS score of 7% indicates a moderate the vulnerability is not listed in the CISA KEV catalog. Exploitation requires a local user that can execute code or otherwise obtain temporary elevated rights; it does not rely on network or remote code execution. Once triggered, the privilege escalation can be used to compromise local resources or pivot to higher-level administrative functions.