CVE-2025-49665 is a high-severity race condition vulnerability identified in Microsoft Windows 10 Version 1809, specifically in the Workspace Broker component. The vulnerability arises due to improper synchronization when concurrently accessing shared resources, classified under CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization). This flaw allows an authorized local attacker to exploit the race condition to elevate privileges on the affected system. The attacker must have some level of local access (low privileges) but does not require user interaction to trigger the exploit. Successful exploitation can lead to full compromise of system confidentiality, integrity, and availability, as the attacker can gain higher privileges than originally granted. The CVSS v3.1 base score is 7.8, reflecting the significant impact and relatively low complexity of exploitation (low attack complexity and privileges required). Although no known exploits are currently reported in the wild, the vulnerability poses a serious risk due to the widespread deployment of Windows 10 Version 1809 in enterprise environments. The absence of a patch link indicates that remediation may still be pending or in progress, necessitating immediate attention from affected organizations.

For European organizations, this vulnerability presents a critical risk to endpoint security, particularly for enterprises still running Windows 10 Version 1809, which remains in use in some legacy or controlled environments. Successful exploitation could allow attackers to escalate privileges locally, potentially bypassing security controls and gaining administrative access. This could lead to unauthorized access to sensitive data, disruption of business operations, installation of persistent malware, or lateral movement within corporate networks. Given the high confidentiality, integrity, and availability impact, organizations in sectors such as finance, healthcare, government, and critical infrastructure are especially at risk. The vulnerability could also be leveraged in targeted attacks or insider threat scenarios, increasing the threat landscape complexity. Additionally, the lack of user interaction requirement facilitates automated or stealthy exploitation, raising the urgency for mitigation in environments with multiple users or shared workstations.

1. Immediate identification and inventory of all systems running Windows 10 Version 1809 within the organization to assess exposure. 2. Apply any available security updates or patches from Microsoft as soon as they are released; monitor official Microsoft security advisories closely. 3. If patches are not yet available, implement temporary mitigations such as restricting local user permissions to the minimum necessary, disabling or isolating the Workspace Broker component if feasible, and enforcing strict access controls on shared resources. 4. Employ endpoint detection and response (EDR) tools to monitor for unusual privilege escalation attempts or suspicious behavior indicative of race condition exploitation. 5. Conduct regular security awareness training to ensure authorized users understand the risks of local privilege escalation and the importance of reporting anomalies. 6. Consider upgrading affected systems to a more recent and supported Windows version where this vulnerability is resolved. 7. Implement application whitelisting and least privilege principles to limit the impact of potential exploitation. 8. Regularly audit and review local accounts and permissions to reduce the attack surface.