Nuclei is a fast and customizable vulnerability scanner based on simple YAML based DSL. In affected versions it a way to execute code template without -code option and signature has been discovered. Some web applications inherit from Nuclei and allow users to edit and execute workflow files. In this case, users can execute arbitrary commands. (Although, as far as I know, most web applications use -t to execute). This issue has been addressed in version 3.3.0. Users are advised to upgrade. There are no known workarounds for this vulnerability.

projectdiscovery/nuclei allows unsigned code template execution through workflows