CVE-2025-59260 is a vulnerability identified in the Microsoft Failover Cluster Virtual Driver component of Windows Server 2016 (build 10.0.14393.0). This flaw allows an attacker who already has authorized local access with low privileges to disclose sensitive information that should otherwise be protected. The vulnerability is categorized under CWE-200, indicating exposure of sensitive information to unauthorized actors. The issue arises because the Failover Cluster Virtual Driver improperly handles or restricts access to certain sensitive data, enabling local attackers to read information beyond their privilege level. The CVSS v3.1 base score is 5.5 (medium severity), with vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, meaning the attack requires local access and low privileges, no user interaction, and results in high confidentiality impact but no integrity or availability impact. The scope remains unchanged, and the exploitability is considered low due to the need for local access and privileges. No public exploits or patches are currently available, but the vulnerability is officially published and reserved since September 2025. This vulnerability is particularly relevant for environments using Windows Server 2016 failover clustering, which is common in enterprise data centers and critical infrastructure for high availability and disaster recovery.

The primary impact of CVE-2025-59260 is unauthorized disclosure of sensitive information within affected Windows Server 2016 failover cluster environments. This can lead to leakage of confidential data such as cluster configuration details, credentials, or other sensitive operational information. While the vulnerability does not allow privilege escalation, code execution, or denial of service, the confidentiality breach could facilitate further attacks by providing attackers with intelligence to plan lateral movement or privilege escalation. Organizations relying on Windows Server 2016 failover clusters for critical services, including financial institutions, healthcare providers, government agencies, and large enterprises, face increased risk of data exposure. The requirement for local access limits remote exploitation, but insider threats or compromised accounts with local access could exploit this vulnerability. The absence of known exploits reduces immediate risk, but the medium severity rating warrants timely mitigation to prevent potential future exploitation.

To mitigate CVE-2025-59260, organizations should implement the following specific measures: 1) Restrict local access to Windows Server 2016 failover cluster nodes strictly to trusted administrators and service accounts; 2) Monitor and audit local user activities on cluster nodes to detect unauthorized access attempts; 3) Apply the official security patch from Microsoft immediately once released; 4) If patching is delayed, consider temporarily disabling or limiting failover cluster virtual driver functionality if feasible without disrupting critical services; 5) Employ network segmentation and access controls to minimize the risk of unauthorized local access; 6) Use endpoint detection and response (EDR) tools to identify suspicious local activities related to cluster components; 7) Review cluster configuration and sensitive data exposure policies to ensure minimal sensitive information is accessible to low-privilege users; 8) Educate administrators about the risks of local privilege misuse and enforce strong credential management and multi-factor authentication for local accounts. These targeted actions go beyond generic advice by focusing on local access control and cluster-specific protections.