CVE-2026-50384 in Windows
Summary
by MITRE • 07/14/2026
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Clip Service allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 07/14/2026
A race condition vulnerability exists in the Windows Clip Service that enables authenticated attackers to achieve local privilege escalation through improper synchronization of shared resources during concurrent execution. This flaw resides in the clipboard service's handling of shared memory segments and temporary files, where multiple processes can access and modify the same resource simultaneously without proper locking mechanisms or atomic operations. The vulnerability manifests when the clipboard service creates temporary files or manipulates shared memory structures that are subsequently accessed by malicious code attempting to exploit the timing window between resource creation and access.
The technical implementation of this race condition stems from inadequate mutex handling and file system permissions within the Windows Clip Service component. When legitimate user processes interact with the clipboard functionality, they may trigger the service to create temporary files in predictable locations such as the %TEMP% directory or other shared system locations. An attacker who has local access can exploit this by rapidly creating competing processes that attempt to manipulate these same temporary resources during the brief window when synchronization mechanisms are not active. This creates opportunities for file replacement attacks, where malicious executables can be placed in locations that will later be executed with elevated privileges.
From an operational perspective this vulnerability represents a significant threat vector for local privilege escalation attacks, particularly within environments where users have standard account access but require elevated privileges to perform administrative tasks. The attack requires only local system access and does not depend on network connectivity or external exploitation methods, making it particularly dangerous in persistent threat scenarios. Security frameworks such as the CWE taxonomy classify this as a race condition vulnerability under CWE-362, which specifically addresses concurrent execution with improper synchronization issues. The ATT&CK framework categorizes this under privilege escalation techniques where adversaries leverage system weaknesses to gain higher level access rights.
The impact of exploitation can range from unauthorized code execution to complete system compromise depending on the attacker's objectives and the specific implementation details of the target Windows version. Mitigation strategies should focus on implementing proper synchronization mechanisms including robust mutex usage, atomic file operations, and privilege separation within the clipboard service components. Microsoft has addressed similar vulnerabilities through regular security updates that include enhanced file access controls and improved inter-process communication protocols. Organizations should implement comprehensive patch management programs to ensure timely deployment of security fixes while also considering additional controls such as restricted user permissions and monitoring for suspicious clipboard service activity patterns.