COLDCARD Seed Generation Flaw Linked to Nearly $89 Million Bitcoin Theft

A firmware integration error in COLDCARD hardware wallets caused seed generation to fall back to a deterministic software RNG (reducing effective entropy to ~40–72 bits), and blockchain analysis has linked this weakness to multiple suspected Bitcoin thefts totaling hundreds to thousands of drained addresses and roughly 1,367.05 BTC observed in one set of transactions; Coinkite published affected models/firmware ranges and recommends generating new seeds on fixed firmware and migrating funds.