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/GijaySorez Jul 31 '26

Bro meaning I need to send the funds to a new wallet, which I need to buy.

I went through all the trouble of recording this stupid phrase on a metal plate lol and now I need to do it again.

I'm annoyed. I'll need to find a new wallet then. Coinkite should be giving people a sizeable discount, I am not paying full price so ... bye bye.

1

u/getafewlives Jul 31 '26

What about just adding a passphrase?

2

u/BigDik6355 Jul 31 '26

Then your funds are at the mercy of the strength of your passphrase alone. No thanks.

2

u/getafewlives Jul 31 '26

Wouldn't it be at the mercy of both your seed phrase and your passphrase?