A heap-based buffer overflow in the Windows kernel enables an authorized local attacker to elevate privileges. Classified as CWE‑822, the flaw allows execution of code with higher authority, effectively compromising the integrity of the affected system. The attack requires the attacker to be authorized and able to run code locally, but does not require network access.

Microsoft Windows 11 version 24H2, Windows 11 version 25H2, Windows 11 version 26H1, Windows Server 2025, and Windows Server 2025 (Server Core installation) are all affected. The vulnerability exists on the 64‑bit editions of these operating systems and can be triggered by any process with local execution rights.

The CVSS score of 7.8 indicates high severity, while the EPSS score of less than 1% indicates a very low probability of exploitation. The vulnerability is not listed in the CISA KEV catalogue, suggesting no widely known exploits are public. The likely attack vector is local privilege escalation, requiring an authorized user to run arbitrary code on the host. Once exploited, the attacker can obtain kernel‑level privileges, disabling security mechanisms and modifying system configurations.