A heap‑based buffer overflow in the Windows kernel enables an attacker who already has authorized local access to gain elevated privileges on the affected system. The flaw allows malicious code to write beyond the bounds of a kernel heap buffer, potentially redirecting control flow or corrupting critical kernel data structures. The result is that an attacker can execute code with kernel‑level privileges, bypassing security boundaries and compromising the confidentiality, integrity, and availability of the host.

Microsoft Windows 11 version 23H2, 24H2, 25H2, 26H2, 26H1 and Windows Server 2022 and Server 2025, including Server Core installations. The vulnerability affects both x64 and ARM64 architectures across these releases.

The CVSS score of 7.8 indicates a high severity with local exploitation. EPSS is not available, so the likelihood cannot be quantified, but the lack of remote vectors reduces the attack surface to attackers with some local presence. The vulnerability is not currently listed in the CISA KEV catalog, suggesting no confirmed exploit activity at this time. Given the kernel‑level impact, the risk remains significant for systems that can be accessed by users with privileged or even standard rights.