CVE-2025-47979 is a vulnerability identified in Microsoft Windows Server 2025, specifically affecting the Server Core installation variant. The issue arises from the Windows Failover Cluster component improperly inserting sensitive information into log files. This vulnerability is classified under CWE-532, which involves the insertion of sensitive data into log files, potentially exposing confidential information to unauthorized parties. An attacker with authorized local access and low privileges (PR:L) can exploit this vulnerability without requiring user interaction (UI:N). The vulnerability does not affect system integrity or availability but compromises confidentiality by allowing sensitive data disclosure. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N) indicates that the attack vector is local, with low attack complexity, and requires privileges but no user interaction. The scope remains unchanged. The vulnerability was published on October 14, 2025, and no public exploits have been reported to date. The affected version is Windows Server 2025 (Server Core) build 10.0.26100.0. The lack of patch links suggests that remediation may be pending or integrated into future updates. This vulnerability is particularly relevant for environments utilizing Windows Failover Clustering for high availability, where log files may contain sensitive operational or configuration data that could be leveraged by an attacker for further attacks or reconnaissance.

For European organizations, the primary impact of CVE-2025-47979 is the potential unauthorized disclosure of sensitive information stored in Windows Failover Cluster log files. This could include configuration details, cluster state information, or other operational data that could aid an attacker in lateral movement or privilege escalation within the network. Although exploitation requires local access with some privileges, insider threats or compromised accounts could leverage this vulnerability to gain additional intelligence. The confidentiality breach could affect organizations in sectors with strict data protection requirements such as finance, healthcare, and critical infrastructure. The vulnerability does not directly affect system availability or integrity, so operational disruption is unlikely. However, the exposure of sensitive cluster information could indirectly increase the risk of more severe attacks. Given the widespread use of Microsoft Windows Server in European enterprise environments, especially in clustered high-availability setups, this vulnerability could have a moderate impact if left unmitigated.

To mitigate CVE-2025-47979, European organizations should implement the following specific measures: 1) Restrict local access to Windows Server 2025 Server Core installations, especially those running Failover Clustering, to trusted administrators only. 2) Review and tighten file system permissions on log directories to prevent unauthorized read access to cluster log files. 3) Monitor and audit access to cluster logs to detect any unusual or unauthorized access attempts. 4) Apply the latest Microsoft security updates and patches as soon as they become available, even though no patch links are currently provided, monitor Microsoft advisories closely. 5) Consider enabling encryption or secure storage mechanisms for sensitive logs if supported by the environment. 6) Use role-based access control (RBAC) to limit the number of users with privileges sufficient to exploit this vulnerability. 7) Implement endpoint detection and response (EDR) solutions to identify suspicious local activities that could indicate exploitation attempts. 8) Educate administrators about the risks of sensitive information leakage through logs and enforce best practices for log management and retention.