The official notice
Defect
On certain vehicles, the wrong over-the-air software update may have been sent for the antilock braking system (ABS). As a result, there could be a loss of power brake assist. This could also cause other systems not to work including the ABS, electronic stability control, traction control, hill start assist and pre-collision assist. Note: This problem would cause ABS warning lights and messages to display on the instrument panel.
Safety Risk
A loss of power brake assist could cause a sudden increase in brake pedal force and lead to an increase in stopping distance. This could increase the risk of a crash. Additionally, vehicle safety systems that don't work could increase the risk of a crash.
Remedy
Ford will notify owners by mail and advise you to take your vehicle to a dealership to update the ABS software.