The 19-year-old German was yet to make his first-team debut for the club since signing his professional contract with the Bundesliga side back in February.
According to police statements, Feierabend was one of the three backseat passengers involved in the collision when the car they were in left the road and hit a tree at 5.45am (4.45am BST) on Sunday.
"This morning we received the terrible news that our 19-year-old forward lost his life after a car crash in the early hours of this morning," said the club in a statement on their website.
Just hours before the teenager had played for Hannover 96's youth team in a game against RB Leipzig, whilst Hanover's reserve team game on Sunday was called off out of respect for Feierabend's family.