Executive brief
A security vulnerability exists in the Microsoft Install Service, a component of the Windows operating system responsible for managing software installations. An attacker who already has basic access to a computer could exploit this flaw to gain full administrative control over the system. This could allow them to view sensitive data, install malicious software, or disrupt business operations.
Technical details
A local privilege escalation vulnerability exists in the Microsoft Install Service (CWE-269). The flaw stems from improper privilege management within the service, which can be exploited by an authenticated attacker with low-level user privileges. By running a specially crafted application, the attacker can elevate their permissions to SYSTEM level. The attack vector is local, requiring the attacker to already have execution capabilities on the target host. Microsoft has released security updates to address this issue across various versions of Windows 10, Windows 11, and Windows Server.
Affected products
- Microsoft Windows 10 Version 1809 10.0.17763.0 to 10.0.17763.9020
- Microsoft Windows 10 Version 21H2 10.0.19044.0 to 10.0.19044.7548
- Microsoft Windows 10 Version 22H2 10.0.19045.0 to 10.0.19045.7548
- Microsoft Windows 11 Version 24H2 10.0.26100.0 to 10.0.26100.8875
- Microsoft Windows 11 Version 25H2 10.0.26200.0 to 10.0.26200.8875
- Microsoft Windows 11 version 26H1 10.0.28000.0 to 10.0.28000.2269
- Microsoft Windows Server 2019 10.0.17763.0 to 10.0.17763.9020
- Microsoft Windows Server 2022 10.0.20348.0 to 10.0.20348.5386
Timeline
- 2026-07-14: advisory: Initial publication by Microsoft and NVD