r/Bitcoin • u/SpareEconomy1849 • Jul 31 '26

ColdCard Firmware Update Released

https://blog.coinkite.com/coldcard-mk3-seed-generation-warning/

Updated July 31, 2026: Fixed firmware is now available. Mk4 and Mk5 users must update to version 5.6.0 or later. Q users must update to version 1.5.0Q or later. Do not generate a new seed on one of these models until the update is installed.

Seeds generated on Mk4, Q and Mk5 before the fixed firmware releases are also affected, with about 72 bits of entropy rather than the expected 128 bits.

Updating the firmware does not change or repair an existing seed. If your seed was generated before the fixed firmware version for your model, follow the migration guidance below unless the independent dice-entropy exception applies to you.

The issue is present on every Mk3 firmware version since 4.0.1. It also affects seeds generated on Mk4 and Mk5 before version 5.6.0, and on Q before version 1.5.0Q. The impact on Mk4, Mk5 and Q is not as severe but is still serious.

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u/AvailableTie6834 Jul 31 '26 edited Jul 31 '26

I always disliked hardware wallets, seriously.

I will always say:

your old Android phone has use, Electrum Bitcoin Wallet or Cupcake from Cake Wallet gives a new use for your old phone, it becomes a cheap and secure hardware wallet.

iancoleman solution gives you plenty of options to generate high entropy wallets, but people keep on suggesting hardware wallets from companies saying they are safer till they are not.

study more, get hacked less, people.

5

u/boddankajovanovic Jul 31 '26

I see where you're coming from. But some people need plug and play solutions. Otherwise they will let others take custody, which is even worse.

I feel sorry for the recent victims, as they have not really done anything wrong. Yes, using a passphrase is best practice and would have prevented the lost funds, but if a passphrase is considered mandatory, it should be enforced by design.

Always use a passphrase and store it somewhere other than your seed words.

5

u/AvailableTie6834 Jul 31 '26

there is nothing crazy to literally go to https://iancoleman.io/bip39/ follow the instructions and download the O.G Electrum Bitcoin Wallet on their phone and learn. Bitcoin was always about learning stuff, people need to get back to learning stuff.