Dishwasher water input doesn't turn off.

We have experienced about a half dozen times when the water won't stop running in, even when we open the door. It has caused the dishwasher to overflow several times. We thought it was clogged and cleaned it out and regularly added vinegar, but tonight we finally saw the problem. For some reason, the water input is not turning off. It's not all the time, just every few weeks, and it apparently eventually turn off. However, tonight we finally had to pull it out and turn off the water supply. What do we do now? Thanks! Karen