To the best of my knowledge, roots in Semitic, both Arabic & Hebrew, do not contain vowels. They are purely consonantal at the base. I read this a couple of years ago about Hebrew in Levin & Rappaport Hovav, Borer, Reinhart amongst many others. I also read this about Arabic in F. Fehri. The problem with these books is that they deal with the notion of root to a marginal extent given that they are not about phonology (these authors are syntacticians).
My question is: are there any roots in Hebrew or Arabic that contain vowels at the base? If yes, please advise some references to read about this point in deep. Thank you.