According to CoinMeta, Coldcard hardware wallets have been exposed to two critical security vulnerabilities, putting users who manage their Bitcoin accounts independently at risk. The engineering and security teams at Block received reports that Bitcoin funds were remotely stolen from non-Bitkey wallets, and subsequently launched an investigation. The investigation revealed that Coldcard MK2, MK3, MK4, Q, and MK5 devices had security flaws. Block stated that the attack initially targeted single-signature wallets and lasted for about an hour, but researchers warn that the attack may still be ongoing. Engineer Max Guise from Block advised affected users to transfer their funds to a secure location as soon as possible. Based on the preliminary analysis by Block, the total amount that may have been stolen has risen to 1,082.59 BTC.