So my understanding is that mining nodes keep unspent transaction outputs in a database which is generated from the ledger. But really the node uses the UTXO database as a short hand for the spendable bitcoins in practice. Not sure how often the UTXO database is validated against the ledger. Maybe once a day or once a week? ( Are there any Bitcoin enthusiasts on this board who might be able to offer an answer?).
So, what would happen if enough UTXO databases were hacked and corrupted at enough nodes? Would they validate a transaction? Even if only temporarily for a few hours, it might be long enough to rip someone off of real cash. How many nodes would need corrupted UTXO databases for such a transaction to validate?
