Do Bouillon Cubes/Powder go bad?
IF...


the jar was tightly sealed and stored in a cool, dry area
the bouillon cubes don't smell spoiled in any way
the cubes aren't off-color
are most likely under 2 years old


then they should be safe. Bouillon can keep for up to 2 years according to stilltasty.com. So, if you think they've been hiding out in the cupboard for over 2 years, I'd toss them.