Is currentMember.getRoles() on the front end secure?

Nothing is SECURE on FRONTEND!
This for you have BACKEND.

If you have sensitive data like …

  1. Passwords
  2. Keys/Serials
  3. Api-activation-codes
  4. some sensitive data inside of your DATABASE
  5. and so on…

Do work with it only on BACKEND!
And use also the Wix-Secrets-API if need.