Yes, due to the European Central Bank database having been compromised, its bank members' financial information is at risk. Though I am not a European Central Bank member, and therefore my own financial information is not currently at risk due to this event, others' personal financial information is at risk.
The larger the internet gets, and the longer it exists - the more experts there are on how to make it work against the average person. Any website, even for financial institutions could potentially be hacked and your information compromised. I don't bank with European Central, but that doesn't make me exempt.
Yes, my financial information is at risk with the compromise of the European Central Bank, because as long as there are humans behind the machines running our banking system, we will always have some degree of risk. Banking information was not safe when it was on paper, either. You take a risk when you bank.
How can we ever know? Even if the ECB says that my data is in the clear, how can they be sure it just hasn't been used or accessed yet? Someone might decide to start using my account number five years from now. I prefer to be a pessimist and assume the worst.