CVE-2025-53726 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) involving a type confusion flaw (CWE-843) within the Windows Push Notifications service. Type confusion occurs when a program accesses a resource or object using an incorrect or incompatible type, potentially leading to memory corruption or unexpected behavior. In this case, the flaw allows an attacker who already has authorized local access to the system to exploit the vulnerability to elevate their privileges. This means the attacker can gain higher-level permissions than originally granted, potentially allowing them to execute arbitrary code with elevated rights, modify system settings, or access sensitive data. The CVSS v3.1 base score is 7.8, indicating a high severity, with the vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, which means the attack requires local access with low complexity, privileges, and no user interaction, but results in high impact on confidentiality, integrity, and availability. No public exploits are known at this time, and no patches have been linked yet, but the vulnerability is officially published and recognized. The vulnerability specifically affects Windows 10 Version 1809, which is an older release but still in use in some enterprise and legacy environments. The nature of the vulnerability suggests that attackers with local access, such as through compromised accounts or insider threats, could leverage this flaw to gain administrative control, making it a significant risk for affected systems.

For European organizations, the impact of CVE-2025-53726 can be substantial, especially in sectors relying on legacy Windows 10 Version 1809 deployments. Successful exploitation could lead to unauthorized privilege escalation, allowing attackers to execute malicious code with elevated rights, potentially leading to full system compromise. This jeopardizes the confidentiality of sensitive data, the integrity of critical systems, and the availability of services. Organizations in finance, healthcare, government, and critical infrastructure sectors are particularly vulnerable due to the sensitive nature of their data and operations. The requirement for local access limits remote exploitation but increases risk from insider threats or attackers who have already gained initial footholds. The absence of known exploits currently reduces immediate risk but also means organizations must proactively patch or mitigate before exploitation becomes widespread. Failure to address this vulnerability could result in data breaches, operational disruptions, and regulatory non-compliance under GDPR and other European data protection laws.

1. Prioritize upgrading or patching Windows 10 Version 1809 systems as soon as Microsoft releases an official security update addressing CVE-2025-53726. 2. Restrict local access to systems running Windows 10 Version 1809 to trusted personnel only, employing strict access controls and monitoring. 3. Implement application whitelisting and endpoint detection and response (EDR) solutions to detect and prevent unauthorized privilege escalation attempts. 4. Conduct regular audits of user privileges and remove unnecessary local administrator rights to reduce the attack surface. 5. Employ network segmentation to isolate legacy systems and limit lateral movement in case of compromise. 6. Use multi-factor authentication (MFA) for local logins where possible to reduce risk from compromised credentials. 7. Monitor system logs and security alerts for unusual activity indicative of privilege escalation attempts. 8. Plan for migration to supported Windows versions to reduce exposure to legacy vulnerabilities.