CZ Warns Bitcoin Holders After $70 Million Wallet Exploit: 'Nothing Is 100%'
Changpeng “CZ” Zhao warned crypto users not to assume hardware wallets are fully safe after a Coldcard flaw enabled a major Bitcoin theft. He said “nothing is 100%” and suggested spreading funds across multiple wallets, while noting no setup is foolproof. The issue stemmed from a Coinkite build error that caused seeds on affected Coldcard devices to use a software fallback instead of the hardware random-number generator, making private keys easier to guess. The bug affected firmware shipped since March 2021, and updating firmware does not fix seeds already generated on compromised devices. Galaxy Research now estimates about 1,196 addresses and 1,082.65 BTC, worth roughly $70.2 million, were drained in a 41-minute window on July 30, far above early estimates. Coinkite has issued emergency hotfixes and told exposed users to create new seeds.
