What are the consequences for someone who masturbated while in a state of Ihram on the the eighth day of Hajj?

The Hajj is valid, and you must repent to Allah for the act of masturbation, as it is forbidden during Hajj and at other times, due to Allah’s saying: (And those who guard their private parts Except from their wives or those their right hands possess, for indeed, they are not to be blamed But whoever seeks beyond that, then those are the transgressors). You are also required to offer a sacrifice (dam) to be slaughtered in Mecca for the poor.