CVE-2025-53355 is a command injection vulnerability identified in the Flux159 mcp-server-kubernetes product, specifically in versions prior to 2.5.0. The mcp-server-kubernetes is an MCP Server component designed to connect to and manage Kubernetes clusters. The vulnerability arises from improper neutralization of special elements in input parameters passed to the Node.js child_process.execSync function. This function executes system commands synchronously, and because the input parameters are not sanitized, an attacker can inject arbitrary system commands. Successful exploitation allows remote code execution (RCE) with the privileges of the server process, which could be significant depending on the deployment context. The vulnerability is classified under CWE-77, which relates to improper neutralization of special elements used in commands, commonly known as command injection. The CVSS v3.1 base score is 7.5, indicating a high severity level. The attack vector is network-based (AV:N), requiring no privileges (PR:N), but does require user interaction (UI:R), and has high impact on confidentiality, integrity, and availability. No known exploits are currently reported in the wild, but the vulnerability is publicly disclosed and fixed in version 2.5.0 of the product. Given the nature of the vulnerability, an attacker could potentially execute arbitrary commands on the host system, leading to full compromise of the server, lateral movement within the network, data exfiltration, or disruption of Kubernetes cluster management operations.

For European organizations using Flux159 mcp-server-kubernetes to manage Kubernetes clusters, this vulnerability poses a significant risk. Exploitation could lead to unauthorized remote code execution, potentially compromising the integrity and availability of critical container orchestration infrastructure. This could disrupt business operations, lead to data breaches, or allow attackers to pivot to other internal systems. Given the widespread adoption of Kubernetes in European enterprises and public sector organizations, especially those managing sensitive or regulated data, the impact could be severe. Additionally, organizations in sectors such as finance, healthcare, and critical infrastructure, which rely heavily on containerized environments, could face regulatory and compliance repercussions if exploited. The requirement for user interaction reduces the likelihood of automated mass exploitation but does not eliminate risk, especially in targeted phishing or social engineering campaigns. The high confidentiality impact means sensitive data could be exposed, while integrity and availability impacts could affect service reliability and trustworthiness of managed Kubernetes clusters.

European organizations should immediately assess their use of Flux159 mcp-server-kubernetes and upgrade to version 2.5.0 or later, where the vulnerability is fixed. Until the upgrade is applied, organizations should implement strict input validation and sanitization controls on any interfaces exposed to untrusted users that interact with the MCP Server. Network segmentation should be enforced to limit access to the MCP Server to trusted administrators and systems only. Employing application-layer firewalls or runtime application self-protection (RASP) solutions can help detect and block suspicious command injection attempts. Monitoring and logging of command execution and unusual process activity on the MCP Server hosts should be enhanced to detect potential exploitation attempts. Additionally, organizations should educate users about the risks of interacting with untrusted inputs or links that could trigger the vulnerability. Finally, implementing the principle of least privilege for the MCP Server process can limit the potential damage in case of exploitation.