Improper validation of the integrity check value in Windows Installer permits a locally authorized attacker to elevate privileges on the system. The flaw allows the attacker to manipulate installer operations and bypass safeguards, potentially granting them elevated accounts or system-level access. This reflects a classic privilege‑escalation weakness, as defined by the relevant security coding standard.

Microsoft Windows 11 versions 23H2, 24H2, 25H2, 26H1, and Microsoft Windows Server 2025 (including Server Core installation). The vulnerability applies across both arm64 and x64 architectures where relevant.

The CVSS score of 7.8 indicates moderate to high severity, and the lack of an EPSS score suggests that the exploit probability is not well quantified yet. The vulnerability is not listed in the CISA KEV catalog, implying no known active exploitation. Attackers would need local, authorized access to exploit the flaw, making it relevant for scenarios where users or services run with higher privileges than intended.