Coinkite recommends that Mk3 users create a strong, unique BIP-39 passphrase on the device and move funds to the resulting wallet.

Coinkite warns Coldcard Mk3 users that firmware versions 4.0.1 to 5.0.3 may have a random number generator flaw compromising wallet seeds.

Bitcoin security experts said the unexplained $38 million wallet drain may involve flawed seed-generation entropy, though the cause and any Coldcard link remain unconfirmed.