CVE-2026-0509: Command Injection in @profullstack/mcp-server

The impact of CVE-2026-0509 is severe due to the potential for remote code execution (RCE). An attacker can inject arbitrary commands through the vulnerable endpoints, gaining complete control over the server. This could lead to data exfiltration, malware installation, denial of service, or any other action the attacker can perform with system-level privileges. The blast radius includes any data stored on the server, as well as the potential for lateral movement to other systems on the network if the server has access to them. This vulnerability is comparable in severity to other command injection flaws that have resulted in significant data breaches and system compromises.

1. Reserved2025-12-09
2. Published2026-02-10
3. EPSS updated2026-03-23

The primary mitigation for CVE-2026-0509 is to upgrade @profullstack/mcp-server to a patched version. As of the publication date, a specific fixed version is not provided, so monitor the project's GitHub repository for updates. As a temporary workaround, input validation and sanitization should be implemented on the /domain-lookup/check and /domain-lookup/bulk endpoints to prevent command injection. Consider implementing a Web Application Firewall (WAF) with rules to detect and block command injection attempts. Regularly scan the application for vulnerabilities using automated tools. After upgrading, verify the fix by attempting to inject a simple command (e.g., whoami) through the vulnerable endpoints – it should be rejected.