Coldcard Wallet Flaw Exposes Years Of Bitcoin Seeds After $70M In BTC Stolen

The Coldcard Exploit Explained: Who Lost Bitcoin and Who's at Risk

Coldcard Mk3 RNG bug reduced seed entropy from 128 to 40 bits, enabling $70M theft from 1,196 wallets on July 30. Hardware isolation failed to protect: affected seeds are permanently weak and require complete regeneration—firmware updates alone won't restore security.