At most. If you dispute fraudulent charges in time, you're not liable for anything. I've even had my CC bank actively call me to discuss fraudulent charges, and that my card would be replaced by the next day.
Someone spent $2,000 at Comcast and Neiman Marcus on my card in one night. I reported it the following day and it was reversed and I was given a new card the same day.
I would love more information from a banker on how the fraud disputes are won. Sometimes the merchant pays, sometimes the bank pays, sometimes it split in percentages. I know it has to do with how the merchant processed the payment or if a pin number was used for the transaction.