CVE-2026-50667 in Windows
Summary
by MITRE • 07/14/2026
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows NTFS allows an authorized attacker to elevate privileges locally.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/15/2026
This vulnerability represents a classic race condition flaw in the Windows NTFS file system implementation that enables local privilege escalation through improper synchronization of concurrent access to shared resources. The flaw occurs when multiple processes or threads attempt to access the same NTFS file system resources simultaneously without adequate locking mechanisms or synchronization primitives. This race condition manifests when an authorized user with legitimate access rights can exploit timing dependencies in the file system operations to gain elevated privileges within the operating system.
The technical implementation of this vulnerability stems from the lack of proper mutual exclusion controls during critical file system operations involving NTFS metadata manipulation, file attribute modifications, or directory structure changes. When concurrent processes attempt to modify shared file system objects such as file permissions, ownership attributes, or security descriptors, the absence of atomic operations creates windows of opportunity for malicious code execution. The flaw specifically affects how Windows NTFS handles resource contention during these operations, where the system fails to properly serialize access to critical data structures that govern file system permissions and access controls.
From an operational perspective, this vulnerability provides a significant attack vector for local adversaries who already possess standard user privileges or limited access rights to the target system. The attacker can craft specific sequences of concurrent operations that exploit the timing gaps in the NTFS implementation to manipulate file system metadata in ways that grant elevated privileges. This type of privilege escalation is particularly dangerous because it requires minimal initial access and leverages legitimate operating system functionality against itself. The attack typically involves creating multiple threads or processes that race to modify the same file system objects while exploiting the temporal window where synchronization checks are not properly enforced.
The vulnerability aligns with CWE-362, which specifically addresses race conditions in concurrent programming scenarios, and demonstrates how improper synchronization can lead to security flaws in operating system components. From an ATT&CK framework perspective, this represents a privilege escalation technique under the T1068 category, where adversaries leverage system-level weaknesses to gain higher privileges. The attack requires careful timing and understanding of the underlying NTFS implementation to successfully exploit the race condition. Mitigation strategies should focus on implementing proper locking mechanisms throughout the file system code path, ensuring atomic operations for critical metadata modifications, and applying timely security patches from Microsoft that address the synchronization gaps in NTFS implementation.
Security professionals should implement monitoring for unusual concurrent file system access patterns and establish proper system hardening measures including regular patch management, implementation of least privilege principles, and careful auditing of file system operations. The vulnerability underscores the importance of thorough testing for race conditions in operating system components and highlights how seemingly benign concurrency issues can have severe security implications when exploited by malicious actors with local access to target systems.