CVE-2025-11546 is an OS command injection vulnerability classified under CWE-78, affecting multiple versions (4.0 to 5.2) of NEC Corporation's CLUSTERPRO X for Linux and EXPRESSCLUSTER X for Linux, including SingleServerSafe variants. The vulnerability arises from improper neutralization of special elements in network packets processed by the cluster management software, allowing an attacker to inject and execute arbitrary operating system commands remotely. Notably, exploitation requires no authentication or user interaction, and the attack vector is network-based, making it highly accessible to remote adversaries. The affected products are designed for high availability and clustering in Linux environments, commonly deployed in enterprise and critical infrastructure settings. The CVSS 4.0 base score of 9.3 reflects the critical nature of this vulnerability, with a vector indicating network attack (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H, I:H, A:H). Although no exploits have been observed in the wild yet, the ease of exploitation and potential for complete system compromise make this a severe threat. The lack of available patches at the time of publication increases the urgency for organizations to implement interim mitigations and monitor for suspicious network activity targeting these products.

The impact of CVE-2025-11546 on European organizations is substantial, particularly for those relying on NEC's cluster management solutions for critical systems. Successful exploitation allows remote attackers to execute arbitrary OS commands without authentication, potentially leading to full system compromise, data breaches, service disruption, and lateral movement within networks. This can severely affect confidentiality by exposing sensitive data, integrity by allowing unauthorized changes, and availability by disrupting cluster operations or causing denial of service. Given the role of clustering software in ensuring high availability, attacks could result in significant downtime for essential services, impacting sectors such as finance, telecommunications, manufacturing, and government operations. The vulnerability's network-based attack vector and lack of required privileges increase the risk of widespread exploitation if left unmitigated. European organizations with regulatory obligations around data protection and operational resilience may face compliance and reputational consequences following an incident involving this vulnerability.

Until official patches are released by NEC Corporation, European organizations should implement several targeted mitigations. First, restrict network access to the affected cluster management interfaces by applying strict firewall rules and network segmentation to limit exposure only to trusted management hosts. Deploy intrusion detection and prevention systems (IDS/IPS) with signatures or anomaly detection tuned to identify suspicious packets targeting CLUSTERPRO X and EXPRESSCLUSTER X protocols. Conduct thorough logging and monitoring of network traffic and system commands on affected servers to detect potential exploitation attempts early. Disable or isolate unused cluster management services where feasible to reduce the attack surface. Engage with NEC support channels to obtain early patch notifications and apply updates promptly once available. Additionally, conduct internal audits to identify all instances of the affected software versions within the environment to prioritize remediation efforts. Educate system administrators on the risks and signs of exploitation to enhance incident response readiness.