Break Enchantment is a spell that is very targetted at curing *exactly* the type of condition Feeblemind causes.

Break Enchantment
Level: Brd 4, Clr 5, Luck 5, Pal 4, Sor/Wiz 5
Components: V, S
Casting Time: 1 minute
Range: Close (25 ft. + 5 ft./2 levels)
Targets: Up to one creature per level, all within 30 ft. of each other
Duration: Instantaneous
Saving Throw: See text
Spell Resistance: No

This spell frees victims from enchantments, transmutations, and curses. Break enchantment can reverse even an instantaneous effect. For each such effect, you make a caster level check (1d20 + caster level, maximum +15) against a DC of 11 + caster level of the effect. Success means that the creature is free of the spell, curse, or effect. For a cursed magic item, the DC is 25.

If the spell is one that cannot be dispelled by dispel magic, break enchantment works only if that spell is 5th level or lower.

If the effect comes from some permanent magic item break enchantment does not remove the curse from the item, but it does frees the victim from the itemís effects.

I realize that Feeblemind specifies that certain spells cure it, but it doesn't say that ONLY these spells cure it. It is merely providing a list of spells which will fix the situation 100% of the time. Break Enchantment still needs a caster level check, unlike higher level spells which reverse the condition automatically.