No, all benzodiazepines have high LD50. LD50 means "median lethal dose", so basically you'd have to take a lot of it to die. It's like several pill bottles for Xanax haha, probably a lot for Valium.
If you read the Wikipedia page it says that benzos replaced barbiturates (aka the drug class N is in) because of low overdose potential.
en.m.wikipedia.org