CVE-2025-53135 is a race condition vulnerability classified under CWE-362, affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw exists within the Windows DirectX component, where concurrent execution using a shared resource is improperly synchronized. This improper synchronization allows an authorized local attacker to exploit the race condition to elevate privileges on the affected system. Specifically, the vulnerability arises when multiple threads or processes access and manipulate shared resources without adequate locking or synchronization mechanisms, leading to inconsistent or unexpected states that can be leveraged to bypass security controls. The attacker must have at least low-level privileges (PR:L) and local access to the system but does not require user interaction (UI:N). The vulnerability has a CVSS v3.1 base score of 7.0, indicating a high severity level. The attack vector is local (AV:L), and the attack complexity is high (AC:H), meaning exploitation requires specific conditions or timing. The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), implying that successful exploitation could lead to full system compromise, including unauthorized data access, modification, and disruption of system operations. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability was reserved in June 2025 and published in August 2025, indicating recent discovery and disclosure. Given that Windows 10 Version 1809 is an older release, many organizations may have upgraded, but legacy systems and certain industrial or embedded environments may still be running this version, making them susceptible to this vulnerability.

For European organizations, the impact of CVE-2025-53135 can be significant, especially for those relying on legacy Windows 10 Version 1809 systems. Successful exploitation allows local attackers to escalate privileges, potentially gaining administrative control over affected machines. This can lead to unauthorized access to sensitive data, disruption of critical business processes, and deployment of further malware or ransomware. Industries such as manufacturing, healthcare, finance, and government agencies that may still operate legacy systems are particularly at risk. The high impact on confidentiality, integrity, and availability means that data breaches, system downtime, and compliance violations (e.g., GDPR) could result. Additionally, the complexity of exploitation and requirement for local access may limit remote attacks but insider threats or compromised user accounts could be leveraged to exploit this vulnerability. The absence of known exploits in the wild currently provides a window for mitigation, but organizations should act promptly to prevent potential future attacks.

1. Upgrade and Patch: Although no official patch links are provided yet, organizations should monitor Microsoft’s security advisories closely and apply patches immediately upon release. Consider upgrading affected systems to supported Windows versions beyond 1809 to reduce exposure. 2. Minimize Legacy Systems: Identify and isolate systems running Windows 10 Version 1809, especially those with DirectX dependencies, and plan for migration or decommissioning. 3. Restrict Local Access: Enforce strict access controls and limit local user privileges to the minimum necessary, reducing the pool of potential attackers who can exploit this vulnerability. 4. Application Whitelisting and Monitoring: Implement application control policies to prevent unauthorized code execution and monitor for unusual privilege escalation attempts or race condition exploitation patterns. 5. Harden Endpoint Security: Deploy endpoint detection and response (EDR) solutions capable of detecting suspicious local privilege escalation behaviors. 6. Conduct Security Awareness: Educate users about the risks of local privilege escalation and insider threats to reduce the likelihood of exploitation. 7. Implement System Integrity Checks: Use tools that verify system file integrity and detect unauthorized changes that could indicate exploitation attempts.