A stack-based buffer overflow in Windows Installer can be triggered by an authorized local attacker to elevate privileges and execute code with higher privileges. The flaw allows the attacker to corrupt control data on the stack, which may grant SYSTEM level rights within the local system context. The primary impact is a local privilege escalation that could enable further attacks or compromise the security of the host.

The vulnerability affects multiple Microsoft Windows releases: Windows 10 versions 1607, 1809, 21H2, and 22H2; Windows 11 versions 23H2, 24H2, 25H2, 26H2, and 26H1; and several Windows Server editions including 2012, 2012 R2, 2016, 2019, 2022, and 2025, along with their Server Core installations.

The CVSS score of 7 indicates a high severity. The EPSS score of < 1% suggests a very low probability of exploitation currently, and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector is local; an attacker with user-level access can supply a crafted installer or otherwise trigger the overflow to gain elevated rights. Because exploitation requires local privileges and the vulnerability is not known to be widely exploited, the immediate risk is moderate, but the potential impact remains significant.