What is the ruling on one who commits "zina" with his hand?

Masturbation, whether by hand or otherwise, is forbidden (haram), based on the Almighty'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 it is those who are the transgressors." The hadith "Cursed is he who marries his hand" was deemed weak by Al-Albani.