CVE-2026-50490 in Windows
Summary
by MITRE • 07/14/2026
Use after free in Windows Installer allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical use-after-free condition within the Windows Installer component that enables local privilege escalation for authenticated attackers. The flaw occurs when the installer service processes certain malformed or crafted installation packages, leading to improper memory management where freed memory blocks are subsequently accessed by malicious code. This specific vulnerability is classified under CWE-416 as a Use After Free condition, which arises from the improper handling of memory resources during software installation processes. Attackers who possess legitimate user credentials can exploit this weakness by crafting specially designed installer packages that trigger the vulnerable code path within the Windows Installer service.
The technical implementation of this privilege escalation vector leverages the elevated privileges of the installer service process, which typically runs with system-level permissions to perform installation operations. When an attacker successfully triggers the use-after-free condition during package processing, they can manipulate the memory layout to overwrite critical function pointers or execute arbitrary code within the privileged context. This attack methodology aligns with ATT&CK technique T1068 which describes local privilege escalation through exploitation of system-level services and processes that operate with elevated privileges. The vulnerability is particularly dangerous because it requires only standard user authentication to exploit, making it accessible to any authenticated user on the system.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete control over the affected system's installation environment. An attacker could install malicious software, modify existing system components, or create persistent backdoors that remain undetected by standard security monitoring tools. The Windows Installer service operates with sufficient privileges to manipulate system files and registry entries, making this vulnerability particularly dangerous for enterprise environments where multiple users may have legitimate access to the system. Additionally, the exploitation process can be automated through malicious installation packages that appear legitimate to unsuspecting users.
Mitigation strategies should focus on immediate patch deployment as provided by Microsoft security updates, which address the underlying memory management issues within the installer service. System administrators should implement least privilege principles and restrict user access to installation capabilities where possible. Network segmentation and monitoring of installer service activities can help detect anomalous behavior that may indicate exploitation attempts. The vulnerability highlights the importance of proper memory management practices in system-level services and reinforces the need for comprehensive code review processes that identify use-after-free conditions before they can be exploited by malicious actors. Security teams should also consider implementing application control measures that restrict execution of potentially malicious installation packages while maintaining legitimate software deployment capabilities for authorized users.