Eating a nut that has gone bad could make you sick to your stomach.
Nuts that have gone bad could cause stomach upset, diarrhea, abdominal pain and stomach cramping or bloating.
However eating bad nuts or rancid nuts is not harmful to your health and you won't get food poisoning from eating bad or rancid nuts.
But the nuts that have gone bad will not be very tasty or pleasant to eat.
So it's better to not eat bad nuts or rancid nuts as some people do experience stomach upset or abdominal cramping.
But some people can eat rancid nuts or bad nuts without any side effects.
You're not gonna die or get deathly sick though from eating any bad nuts though.