$70 Million in Bitcoin Stolen via Coldcard Hardware Wallet Flaw

A major security flaw in Coldcard hardware wallets has led to the theft of approximately $70.2 million worth of Bitcoin, according to reports.

The issue stems from a March 2021 firmware integration error that incorrectly routed seed generation, allowing an attacker to reproduce candidate output streams offline and drain vulnerable addresses.

Coldcard's manufacturer, Coinkite, has released emergency firmware updates for all affected models and release tracks, but installing the new firmware does not repair seeds already exposed by the flaw.