CVE-2025-62801 is a command injection vulnerability classified under CWE-78 affecting the FastMCP framework developed by jlowin, specifically versions prior to 2.13.0. FastMCP is a standard framework used to build MCP applications, commonly deployed on Windows hosts. The vulnerability arises due to improper neutralization of special elements in the server_name field, which can be manipulated by an attacker to inject and execute arbitrary operating system commands. This flaw allows an attacker with the ability to influence the server_name field to escalate privileges and execute commands on the underlying Windows system, potentially leading to full system compromise. The vulnerability requires low attack complexity but does require partial privileges (PR:L) and user interaction (UI:A), as indicated by the CVSS 4.0 vector. The impact on confidentiality, integrity, and availability is high since arbitrary commands can be executed, potentially leading to data theft, system manipulation, or denial of service. Although no known exploits are currently reported in the wild, the vulnerability is publicly disclosed and fixed in FastMCP version 2.13.0. The lack of network attack vector (AV:L) suggests local or limited network access is necessary for exploitation. The vulnerability does not require scope change or authentication bypass but does require some level of privilege and user interaction, which somewhat limits the ease of exploitation but still poses a significant risk to affected systems.

For European organizations, this vulnerability poses a significant risk especially to those using FastMCP on Windows platforms in critical infrastructure, industrial control systems, or enterprise environments. Successful exploitation could lead to unauthorized command execution, allowing attackers to compromise system confidentiality by accessing sensitive data, integrity by modifying or deleting files and configurations, and availability by disrupting services or causing system crashes. Given FastMCP's role in building MCP applications, which may be integral to operational technology or business-critical applications, the impact could extend to operational disruptions and financial losses. The requirement for partial privileges and user interaction reduces the risk of widespread automated exploitation but does not eliminate targeted attacks, particularly insider threats or phishing campaigns aimed at gaining the necessary access. The absence of known exploits in the wild provides a window for proactive mitigation. However, organizations with legacy FastMCP versions remain vulnerable and must act swiftly to prevent potential compromise.

European organizations should immediately upgrade all FastMCP installations to version 2.13.0 or later, where the vulnerability is patched. Where immediate upgrade is not feasible, restrict access to the server_name field by implementing strict input validation and sanitization to neutralize special characters that could be used for command injection. Employ application-layer firewalls or host-based intrusion prevention systems to detect and block suspicious command execution attempts. Limit user privileges to the minimum necessary to reduce the risk of privilege escalation. Conduct regular audits and monitoring of logs for unusual command execution patterns or unauthorized changes. Educate users about the risks of social engineering and phishing that could lead to the required user interaction for exploitation. Implement network segmentation to isolate critical systems running FastMCP from less secure network zones. Finally, maintain an up-to-date asset inventory to quickly identify and remediate vulnerable instances.