The Template Controller is a powerful controller that is able to create/apply arbitrary objects from templates and an input matrix. This has some security implications as it requires you to make sure that you don't open potential security vulnerabilities inside your cluster.

This means, you must make sure that your ObjectTemplate objects are either not dependent on external inputs (which might contain malicious input) or tha the used service account is restricted enough to not allow malicious modifications to the cluster.

Especially watch out when using the cluster-admin (or comparable) role. It can easily lead to privilege escalation if templates and inputs are too dynamic.