CVE-2025-59260 is a vulnerability identified in the Microsoft Failover Cluster Virtual Driver component of Windows Server 2019 (build 10.0.17763.0). It is classified under CWE-200, indicating an exposure of sensitive information to unauthorized actors. The flaw allows an attacker who already has authorized local access with low privileges to disclose sensitive information that should otherwise be protected. The vulnerability does not require user interaction and does not affect system integrity or availability, but it compromises confidentiality by leaking potentially sensitive cluster-related data. The attack vector is local (AV:L), with low attack complexity (AC:L) and requires privileges (PR:L), but no user interaction (UI:N). The scope remains unchanged (S:U), meaning the impact is limited to the vulnerable component without affecting other system components. The CVSS v3.1 base score is 5.5, reflecting a medium severity level primarily due to the confidentiality impact. No known exploits are currently in the wild, and no patches have been published yet. The vulnerability could be leveraged by insiders or attackers who have gained limited local access to gather information useful for further attacks or lateral movement within clustered server environments. The Failover Cluster Virtual Driver is critical in high-availability setups, so exposure of sensitive data here could have operational security implications.

For European organizations, especially those operating critical infrastructure or enterprise environments relying on Windows Server 2019 failover clustering, this vulnerability poses a confidentiality risk. Exposure of sensitive cluster information could facilitate reconnaissance by malicious insiders or attackers who have gained local access, potentially enabling privilege escalation or lateral movement. Although the vulnerability does not directly affect system integrity or availability, the leaked information could undermine security postures and lead to more severe attacks. Organizations in sectors such as finance, healthcare, telecommunications, and government, which often use clustered Windows Server environments, could be particularly impacted. The requirement for local access and privileges limits the threat to internal actors or attackers who have already breached perimeter defenses, but the risk remains significant in environments with multiple users or shared access. Failure to address this vulnerability could result in data breaches or operational disruptions stemming from subsequent attacks leveraging the disclosed information.

Since no patches are currently available, European organizations should implement strict access controls to limit local access to Windows Server 2019 systems running failover clusters. Employ role-based access control (RBAC) to ensure only trusted administrators have the necessary privileges. Monitor and audit local access logs and cluster-related activities to detect unusual behavior indicative of exploitation attempts. Use endpoint detection and response (EDR) tools to identify suspicious processes or data access patterns. Segregate cluster nodes and restrict administrative access to dedicated management networks to reduce exposure. Prepare to deploy official patches promptly once released by Microsoft. Additionally, conduct regular security awareness training for administrators to recognize and report potential insider threats. Consider implementing multi-factor authentication (MFA) for local administrative accounts to further reduce risk. Finally, review and harden cluster configurations to minimize unnecessary data exposure.