What are the potential pitfalls of including external files in a PHP script for Cronjobs?

Including external files in a PHP script for Cronjobs can lead to security vulnerabilities if the included files are not properly sanitized. To mitigate this risk, it is important to ensure that the included files are from trusted sources and do not contain any malicious code.

// Example of including an external file in a PHP script for a Cronjob
include '/path/to/external/file.php';
// Make sure to sanitize the included file before executing it