CVE-2025-59209 is a vulnerability classified under CWE-200 (Exposure of Sensitive Information) affecting Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). The vulnerability resides in the Windows Push Notification Core component, which is responsible for handling push notifications on the system. An authorized attacker with local access and low privileges can exploit this flaw to disclose sensitive information stored or processed by this component. The vulnerability does not require user interaction and does not allow modification or disruption of system operations, limiting its impact to confidentiality breaches only. The CVSS v3.1 score is 5.5 (medium), reflecting the local attack vector, low complexity, and high confidentiality impact but no integrity or availability impact. No public exploits or active exploitation in the wild have been reported as of the publication date (October 14, 2025). The vulnerability was reserved on September 10, 2025, and is currently published without an available patch, indicating that mitigation relies on access control and monitoring until a fix is released. The exposure of sensitive information could include user data or system details accessible through the notification service, potentially aiding further attacks or privacy violations.

For European organizations, this vulnerability poses a risk primarily to confidentiality, potentially exposing sensitive user or system information to unauthorized local actors. This could lead to privacy breaches, leakage of internal system details, or information useful for lateral movement within networks. Although the vulnerability requires local access with low privileges, insider threats or compromised endpoints could exploit it. Critical sectors such as finance, healthcare, and government agencies in Europe, which often use Windows 11 25H2, may face increased risk if attackers gain local access. The lack of impact on integrity and availability reduces the risk of direct operational disruption, but information exposure could facilitate subsequent attacks or compliance violations under GDPR. Organizations with shared workstations or less stringent local access controls are particularly vulnerable. The absence of known exploits in the wild currently limits immediate risk but does not preclude future exploitation once details become widely known.

1. Restrict local access to Windows 11 25H2 systems, ensuring only trusted and authorized users can log in, especially on devices handling sensitive data. 2. Implement strict endpoint security controls, including application whitelisting and behavior monitoring, to detect anomalous access to the Windows Push Notification Core. 3. Monitor local system logs and notification service activity for unusual patterns that may indicate exploitation attempts. 4. Apply the official security patch from Microsoft promptly once it becomes available; track Microsoft security advisories closely. 5. Use least privilege principles to limit user rights on affected systems, reducing the attack surface. 6. Educate users and administrators about the risk of local privilege misuse and enforce policies to prevent unauthorized physical or remote local access. 7. Consider network segmentation and endpoint isolation for critical systems to limit lateral movement opportunities if local compromise occurs. 8. Maintain up-to-date backups and incident response plans to quickly address any potential data exposure incidents.