I have already submitted my Ph.D. thesis to my committee and plan to defend my thesis. I want to prepare an updated CV.
In my situation, what should I write in the CV:
Typically, one writes Ph.D., 2018 (expected).
If you have a short description (e.g., bullet points) after this heading, you can also put the expected graduation/defense month or something to the effect of "thesis submitted 25 May 2018" in this area.
If you have not yet been awarded your PhD, do not put down that you have it.
If you haven't defended yet, I would list (expected).
If you have defended and committee passed and thesis turned in and ruler lady passed and all done, done but are just waiting for the 6 month wheels to churn and send you a sheepskin, I would keep it simple and just list the Ph.D. as done. If you stop using months on your CV and move to years, this helps you.