Coldcard 5.6.1 Is Here: Why the Update Will Not Rescue Your Old Seed

Coinkite shipped firmware 5.6.1 for the Coldcard Mk4 and Mk5 and 1.5.1Q for the Q model on August 20, 2026. If you own a Coldcard, you need to keep two things apart. The update closes the gap for everything you create from now on. It does not repair a seed that was generated on a faulty release. For that seed, the only remedy is a move to a freshly generated recovery phrase. The maker says so in plain terms in its notice: “Installing this update does not make an existing vulnerable seed safe.” The status page at coldcard.com/security/status puts it even more briefly: “An update is not a seed migration.” That means anyone who set up their device between March 2021 and July 2026 and has used the same recovery phrase ever since is affected. In that case the update alone is not enough, not even when the Coldcard shows the new version number afterwards. Coldcard 5.6.1 and 1.5.1Q: What the maker shipped on August 20 The two releases are the result of a three-week review Coinkite began after the emergency update of July 31. They replace releases 5.6.0 and 1.5.0Q, which were pushed out quickly at the time, and they go beyond a plain bug fix. You can read the release off the file name. The ...