The Windows Installer component contains a numeric truncation error that can be triggered by an authorized local user to elevate their privileges. This flaw allows an attacker to gain higher privilege on the affected system, potentially enabling the installation of malicious software, modification of system settings, or execution of arbitrary code with administrative rights. The underlying weakness is a combination of stack‑based buffer overrun (CWE‑121) and numeric truncation (CWE‑197) that leads to unauthorized privilege escalation.

Microsoft Windows 10 releases from version 1607 through 22H2, Windows 11 releases from 23H2 through 26H2 (including the 26H1 release), and all supported Windows Server editions from 2012 to 2025—including Server Core installations—are impacted. Both x86/x64 and arm64 variants are affected as indicated by the CPE identifiers, so any machine running these operating systems is potentially vulnerable.

The vulnerability has a CVSS score of 7.8, indicating a significant risk when exploited. Although an EPSS score is not available, the local exploitation requires the attacker to be already authorized on the system and could be executed via the Windows Installer service. The vulnerability is not listed in the CISA KEV catalog, but given its severity, organizations should treat it as a high‑priority risk. While the attack vector is local, any compromise of a user account could lead to full administrative control of the machine.