CVE-2026-62690 in Windows
Summary
by MITRE • 08/11/2026
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a classic race condition flaw in the Windows Push Notifications service that enables local privilege escalation through improper synchronization of shared resources during concurrent execution. The underlying issue stems from inadequate mutex or semaphore implementation when multiple processes or threads attempt to access shared system resources simultaneously without proper coordination mechanisms. According to CWE-362, this classification identifies the fundamental weakness where two or more threads can execute concurrently and share access to a resource, leading to unpredictable behavior and potential security implications. The vulnerability exists within the Windows Push Notifications subsystem where the service fails to properly enforce exclusive access to critical system components during notification processing operations.
The technical exploitation occurs when an authorized local attacker leverages this race condition to manipulate shared resources that control privilege levels or system access controls. During concurrent execution scenarios, the timing window between resource checking and resource modification creates opportunities for malicious code to insert itself into the execution flow or modify critical data structures before legitimate processes complete their operations. This flaw specifically affects the Windows Push Notifications service which handles background notification delivery and system integration tasks that require elevated privileges. The improper synchronization manifests when multiple threads attempt to access shared kernel objects or registry keys without proper locking mechanisms, allowing one thread to observe a resource in an inconsistent state while another modifies it.
From an operational perspective, this vulnerability presents significant risk as it requires only local authentication to exploit, making it particularly dangerous in environments where users may have legitimate access to systems but should not possess elevated privileges. The privilege escalation occurs through manipulation of notification handling processes that typically operate with higher privileges than the user context, allowing attackers to effectively bypass standard access controls and gain system-level permissions. This vulnerability aligns with ATT&CK technique T1068 which covers privilege escalation through race conditions in Windows systems. The impact extends beyond simple local elevation as it can potentially allow attackers to establish persistent access or move laterally within networks where compromised systems serve as entry points.
Mitigation strategies should focus on implementing proper synchronization mechanisms including mutexes, semaphores, or other atomic operations that prevent concurrent access to shared resources during critical sections of code execution. Microsoft recommends applying the latest security updates and patches that address the specific race condition in the Push Notifications service, which typically involve correcting the timing and locking mechanisms within the vulnerable subsystem. System administrators should also implement least privilege principles and monitor for unusual notification processing behavior that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper concurrent programming practices in system-level services where multiple threads or processes interact with shared resources, emphasizing the need for comprehensive testing of race condition scenarios during development cycles and security reviews of kernel-level components.