Is it okay if my ledger board overlaps my foundation wall?
It's only a problem to the extent that you're hanging common joists on the unsupported portion of the ledger and therefore relying on the integrity of the woodgrain. If your joist hangers only attach on the upper portion, where the ledger is well attached to the framing, I see no concern.

If your hanger attachment extends lower than that, either anchor to the foundation as well or look for structural hardware that carries the entire ledger from the bottom and mounts to the framing. I've used this one on ICF projects, and it would probably work well without the embedded inner portion and the right screws.