PROTECT YOUR SOVEREIGNTY.
Coinkite named the flaw. Named the affected firmware. Published the migration path. If you generated a seed on a Coldcard Mk3 running firmware 4.0.1 (March 2021) or later without a BIP-39 passphrase, tonight is the night to move. Mk4, Q, and Mk5 are unaffected. Dice-only seeds are unaffected. Passphrase-protected wallets are at minimal risk. Everything else generated on that firmware line, over the past four years, needs a plan by morning. Three paths, in order of preference.
Path 1 · BestGenerate a new seed on an unaffected Coldcard — Mk4, Q, or Mk5. Record and verify the backup before depositing funds. Verify a new receive address on the device screen. Send a small test transaction and confirm it lands. Only then move the remainder. Keep the old backup until the entire migration is confirmed.
Path 2 · Interim (Mk3 only)Create a strong, unique BIP-39 passphrase on the Mk3 — this is the passphrase, not the PIN. The passphrase adds a 25th word an attacker doesn’t have, effectively creating a new wallet on top of the potentially-compromised seed. Move funds from the original wallet to the new passphrase-protected wallet. Back up the passphrase separately from the seed words. Verify the eight-digit XFP fingerprint every time. Treat as an interim hedge until you can migrate to an unaffected device.
Path 3 · AdvancedDice-only migration on the Mk3 itself. On an empty Mk3 running firmware 4.1.9, select Import Existing > Dice Rolls and enter at least 99 independent rolls of a fair six-sided die. This dedicated dice path hashes the roll sequence directly and does not touch the device’s random-number generator. The dice sequence is secret key material — never photograph it, save it digitally, or enter it into a networked computer.
Every migration requires calm. Rushing a wallet move creates a more immediate risk than the vulnerability you’re fixing. Verify XFP. Verify receive addresses on-device, not on a computer screen. Small test transactions before the remainder. Keep the old backup until the new wallet is confirmed. The vendor did the mature thing tonight. The operator does the mature response.
Sovereignty is a practice, not a purchase.
Coinkite · Mk3 Security Advisory · thu jul 30 2026
MORE ON THE DEFENSIVE STACK
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