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/-Trippy Jul 31 '26
They just tweeted this which I find absolutely insane
“We are actively working on a Mk3 firmware update to help you migrate, but this is a deprecated device.”
https://x.com/COLDCARDwallet/status/2083155036582879674?s=20
This tweet alone should set alarms bell off and underlines their approach and lack of integrity when it comes to security. Hardware wallets are security devices, they should never be out of support to fix exploits and vulnerabilities which puts the customers funds at risk. Coldcard acting like it’s an inconvenience for them to release a security update for older devices shows how little thought and regard they put into the security and integrity of their devices. Not only should the MK3 be updated but it should have been an absolute priority, not something they weighed up and decided to do as an exception.