Even if they repeated it, it’d just be hearsay.
That’s why you confess your sins to God
Put yourself in the priest’s shoes. Someone just walked into confession and told you that he molests children. As a priest, you can’t go to the authorities.
A heard a priest say that his options are to encourage the man to seek help, to go to the police and turn himself in.
The priest does not have to give absolution right then and there. He can give some sort of conditional a solutions provided he stopped his sinful acts.
It’s a no-win situation.