cron lacks permissions to run a script

I have a script (which backs up, using rclone) that I run from the Terminal or Automator after chmod a+x with no permissions problems. When this script is run in cron (or launchd), stderr shows "/bin/bash: /Users/joshua/script.sh: Operation not permitted." This approach works fine in Ubuntu. Edit: The above question remains relevant, but note that launchd is the favored cron replacement for Mac, while Automator is available for application-level scheduling.