New Zealand striker Chris Killen slotted the opener for Hibernian in the 47th minute on the penalty spot from a low ball by Merouane Zemmama who pounced on a defensive blunder by Aberdeen's Zander Diamond.
The Moroccan midfielder pounded down the left and squared the ball to Killen who steered home his left foot shot.
Aberdeen levelled with a fine turn and shot from 15 metres by Lee Miller who sent the ball into the bottom left-hand corner of the net in the 56th minute. There was more misery for Hibernian when Killen was sent off for his second bookable offence after clattering Gary Dempsey in the 66th minute.
Severin blasted a knee-high shot from 25 metres past keeper Zibi Malkowski into the left side of the net in stoppage time.
Aberdeen moved fourth from top with 18 points from 12 games while Hibernian have 15 from 12. Champions Celtic head the table with 31 from 12.