Coffee can sometimes overflow from the basket; this would be due to a few different reasons such as the filter placement or even the coffee grounds being too fine. Please turn off the appliance and check the filter placement, replace, and try again. If the problem persists then it could be due to the coffee itself; potentially the ground is so fine the water is not flowing through quick enough and therefore causing the water to overflow. The recommended solutions are to change the type of coffee grounds to one that is coarser or consider a different type of filter such as a reusable one.