A heap‑based buffer overflow in the Windows kernel allows an authorized local attacker to elevate privileges. Classified as CWE‑822, the flaw enables execution of code with kernel‑level authority, providing elevated local access to the attacker.

Windows 11 versions 24H2, 25H2, and 26H1, as well as Windows Server 2025, including Server Core installations, on both 64‑bit and arm64 architectures.

The CVSS score of 7.8 indicates high severity, while the EPSS score of 5% indicates a low probability of exploitation. The vulnerability is not listed in the CISA KEV catalogue, implying no widely known public exploits. The likely attack vector is local privilege escalation, requiring an authorized user to execute code locally. Once exploited, the attacker can obtain kernel‑level privileges, providing elevated local access to the affected system.