A stack‑based buffer overflow in the Windows kernel can be triggered by an authorized local user, allowing that user to gain higher privileges than intended. This flaw pertains to the CWE‑121 weakness, where improper stack handling may lead to code execution at kernel level. The vulnerability can be used to read, modify, or execute memory within the kernel, potentially compromising the entire operating system.

Microsoft Windows 11 version 26H1 on arm64 processors is affected by the stack overflow flaw. No other versions or variants are listed in this entry.

The CVSS score of 7 indicates a high severity risk. The EPSS score is not available, and the issue is not included in CISA's Known Exploited Vulnerabilities catalog. Exploitation requires local access to the system; an attacker with authorized privileges can trigger the buffer overflow and achieve system‑wide execution authority. The lack of publicly available exploits suggests that active exploitation is limited to determined internal threats able to launch the exploit locally.