joint CD's with a deceased family member

[lilyfil4]

My Grandmother just died recently and I am exectutor of her will. She has CD's in her name and in the name of a grandchild. I wonder now that she is passed away can the grandchildren cash in the CD with a death certificate? Or does it all need to wait for the will to be probated. I would think the CD belongs to them now that she is gone. Thanks for your help.