A target with HP leak status will lose 60 HP at maximum unless the battle is immediately over.
A lesser known fact is that Holy/White deals HP leak status, but you normally don't see this occuring.
This is because it is linked to the Holy elemental and if and only if the target is weak vs the elemental
(in this instance, Holy), then the target becomes inflicted with HP leak status.
Note that the HP Leak timer is reset on another attack that includes HP status.