A faulty brake light switch is the reason for the massive recall.

Subaru will soon announce the recall of 1.3 million Impreza and Forester vehicles due to a faulty brake light switch. Brake function will not be affected but rear brake lights may fail to ignite. Affected vehicles were produced from 2008 - 2017. The recall has not been officially announced yet but Reuters broke the news of the recall and that vehicle owners will be notified via first class mail.