If the Tangem Wallet card is stolen, can a third party gain access to the wallet?

A third party will only be able to access your wallet if your cards are not linked (you have not backed them up). In this case, access code protection is not available: it is activated only when you link two or three cards to one wallet.
That's why we recommend that you make backups before funding your wallet, ensuring that your funds are protected by the access code. Moreover, the card will be protected against brute-force attacks. After the sixth incorrect attempt to enter the code, the delay time for the next attempt is increased by 1 second. The maximum delay time is 45 seconds. The delay is only reset after the access code has been successfully entered.