A heap-based buffer overflow exists in the Windows Kernel that allows an attacker who has local authorization to gain higher privileges on the affected system. The flaw resides in the kernel heap and could be leveraged to execute arbitrary code with kernel privilege, thereby compromising confidentiality, integrity, and availability of the entire system. The vulnerability is identified as CWE-122.

Affected products include Microsoft Windows 10 releases 1809, 21H2, and 22H2, Microsoft Windows 11 releases 23H2, 24H2, 25H2, 26H2, and 26H1, as well as Microsoft Windows Server 2019 (standard and Server Core), Windows Server 2022, and Windows Server 2025 (both standard and Server Core).

The CVSS base score of 7.8 reflects a high severity with local access required. EPSS data is not available, so the current exploitation likelihood cannot be quantified. The vulnerability is not listed in the CISA KEV catalog, indicating no confirmed widespread exploitation yet, but the presence of a kernel heap overflow warrants caution. The likely attack path involves an authorized user triggering the overflow through specific privileged operations, granting them kernel-level execution.