Coldcard Mk3 Users Warned of Risk After 594 BTC Swept From 500 Addresses

The company said the latest advisory reflects its early analysis and that a formal technical review will follow. Coinkite, the Canadian company behind the Coldcard hardware wallet, has warned users that Bitcoin funds may be at risk if their wallet seed was generated on certain affected firmware versions. The company said the issue affects every Mk3 firmware release since version 4.0.1, released in March 2021, and is linked to the device-generated entropy used when creating seeds. Funds Still at Risk Seeds generated on Mk4 and Mk5 before firmware version 5.6.0, and on Q before version 1.5.0Q, are also affected, although Coinkite said the impact on those models is less severe but remains serious. According to the company, affected seeds have around 72 bits of entropy instead of the expected 128 bits. According to the update, TAPSIGNER, OPENDIME, and SATSCARD are not affected because they use different codebases. Coinkite urged users with affected ones to migrate their funds to a newly generated seed on an unaffected device. The company said Mk4 and Mk5 users should first upgrade to firmware version 5.6.0 or later, while Q users should install version 1.5.0Q or later before generating...