CVE-2025-47979 is a vulnerability classified under CWE-532, which pertains to the insertion of sensitive information into log files. Specifically, this issue affects the Windows Failover Cluster component in Microsoft Windows Server 2025 Server Core installations (version 10.0.26100.0). The vulnerability allows an authorized attacker with local access and low privileges (PR:L) to obtain sensitive information by reading log files where such data is improperly recorded. The CVSS 3.1 base score is 5.5 (medium), reflecting that the attack vector is local (AV:L), requires low attack complexity (AC:L), and privileges (PR:L), but no user interaction (UI:N). The impact is primarily on confidentiality (C:H), with no impact on integrity or availability. The vulnerability does not require user interaction and affects only the local system scope. No known exploits have been reported in the wild, and no patches have been linked yet. The root cause is the improper handling of sensitive data by the Failover Cluster logging mechanism, which inadvertently writes sensitive information into logs accessible to authorized users. This can lead to unauthorized disclosure if log file access controls are insufficient. The vulnerability was reserved in May 2025 and published in October 2025, indicating recent discovery and disclosure. Organizations using Windows Server 2025 Server Core with Failover Clustering should be aware of this issue and monitor for patches or guidance from Microsoft.

For European organizations, the primary impact of CVE-2025-47979 is the potential unauthorized disclosure of sensitive information stored in log files on Windows Server 2025 Server Core installations running Failover Clustering. This can lead to confidentiality breaches, exposing internal operational details or sensitive cluster configuration data to unauthorized local users. While the vulnerability does not affect system integrity or availability, the exposure of sensitive data can facilitate further attacks or compliance violations, especially under strict data protection regulations such as GDPR. Organizations relying on clustered Windows Server environments for critical applications, databases, or services may face increased risk if local access controls are weak or if multiple users share administrative or operational access. The medium severity rating reflects that exploitation requires local access and privileges, limiting the attack surface primarily to insiders or compromised accounts. However, given the strategic importance of clustered services in enterprise and data center environments, the impact on business continuity and regulatory compliance can be significant if sensitive data is leaked. European entities in finance, healthcare, government, and critical infrastructure sectors using this platform should prioritize assessment and mitigation.

1. Restrict local access to Windows Server 2025 Server Core systems running Failover Clustering to only trusted and authorized personnel. 2. Review and tighten file system permissions on log directories and files to ensure that sensitive logs are accessible only to necessary administrative accounts. 3. Implement strict auditing and monitoring of log file access to detect unauthorized reading or copying of sensitive information. 4. Follow Microsoft’s security advisories closely for the release of patches or configuration guidance addressing this vulnerability and apply updates promptly. 5. Consider disabling or limiting Failover Clustering logging verbosity if feasible until a patch is available, to reduce sensitive data exposure. 6. Employ endpoint protection and local privilege management to prevent unauthorized escalation or lateral movement that could enable exploitation. 7. Conduct internal security awareness and training to highlight the risks of local information disclosure and enforce least privilege principles. 8. Use centralized and secured log management solutions that can ingest logs securely without exposing sensitive data on local servers. These steps go beyond generic advice by focusing on access control, monitoring, and operational practices specific to the affected component and environment.