CVE-2026-85333 in Windows
Summary
by MITRE • 10/14/2026
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Performance Monitor allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 10/15/2026
The vulnerability described constitutes a classic race condition within the Windows Performance Monitor subsystem, specifically arising from concurrent access to shared resources without adequate synchronization mechanisms. In software engineering and security architecture, this type of flaw is formally categorized under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization. The core technical issue lies in the temporal gap between a check for resource availability or state and the subsequent use of that resource. During this window, an attacker who has already authenticated to the system can manipulate the execution flow by rapidly executing multiple threads or processes that interact with the same memory space or file handle managed by the Performance Monitor service. This manipulation allows the attacker to alter critical data structures before they are properly locked or validated by the operating system kernel, effectively bypassing intended security controls and state checks.
From an operational perspective, this race condition enables local privilege escalation, allowing a low-privileged user account to gain higher-level permissions, potentially reaching SYSTEM level access depending on the specific implementation details of the affected Windows version. The impact is severe because it undermines the fundamental principle of least privilege that governs operating system security models. An attacker leveraging this flaw can execute arbitrary code with elevated privileges, install malware, create new administrative accounts, or exfiltrate sensitive data stored in protected areas of the file system and registry. This capability transforms a standard user account into a powerful entry point for further lateral movement within an enterprise network, as the compromised high-privilege account can be used to target other systems that trust the initial host based on its elevated status.
The exploitation technique aligns with MITRE ATT&CK tactic T1068: Exploitation for Privilege Escalation, specifically falling under subtechniques related to exploiting software vulnerabilities in operating system components. The attacker typically utilizes a crafted application or script that triggers the specific API calls within Windows Performance Monitor repeatedly and concurrently to increase the probability of winning the race condition. This requires precise timing and often involves techniques such as thread priority manipulation or memory corruption attempts to ensure the shared resource is accessed at the exact moment when synchronization locks are not yet applied or have been released prematurely by the operating system scheduler.
Mitigation for this vulnerability primarily relies on applying vendor-provided security patches that address the underlying code defects in the Windows Performance Monitor component. These updates typically introduce proper locking mechanisms, such as mutexes or critical sections, to ensure atomicity of operations involving shared resources. Until patches are applied, administrators should enforce strict access controls by limiting who can execute performance monitoring tools and configuring group policies to restrict local logon rights where feasible. Additionally, deploying endpoint detection and response solutions that monitor for unusual patterns of concurrent API calls or rapid privilege changes can help detect exploitation attempts in real-time. Regular vulnerability scanning and timely application of cumulative updates remain the most effective defense against such race condition vulnerabilities in legacy systems.