Coldcard released firmware versions 5.6.1 (Mk4/Mk5) and 1.5.1Q (Q), requiring new mnemonics to include at least 65 irregular keystrokes, 50 physical dice rolls, or 128 physical coin rolls as user entropy sources. The new firmware adds PSB verification before signing, strengthens USB connection, Delta Mode isolation mechanism, and initializes the random number generator. Updating firmware cannot fix existing mnemonics. Coldcard reminds affected users to generate new mnemonics after updating their devices and migrate funds to the new wallet. It also recommends that all users verify the firmware signature.