EL7.AI
CryptoMediumUpdated×3•Originally published 1 August 2026•Updated 1 August 2026•
2 min read

Coldcard Firmware Bug Leads to $38M Bitcoin Theft

Digital art of a Coldcard device, a safe with 'Seed Flaw' text, and Bitcoin coins spilling from a red pipe.

Key Facts

1A build error in Coinkite's firmware reduced wallet entropy from 128 bits to just 40 bits.
2An attacker used AI to exploit the flaw, draining 500 wallets within a 25-minute window.

In a move that highlights the escalating cybersecurity risks within the digital asset sector, Coldcard hardware wallets suffered a major security breach due to a firmware build error by Coinkite. According to reports, this technical flaw reduced wallet encryption entropy from 128 bits to just 40 bits, rendering private keys vulnerable to brute-force discovery. An attacker utilized AI to identify the vulnerability, successfully draining 500 wallets within a 25-minute window, resulting in the theft of approximately $38 million in Bitcoin.

This crisis arrives at a sensitive time for the cryptocurrency market, raising significant concerns regarding the reliability of cold storage solutions typically viewed as the gold standard for security. The data indicate the bug has been present since March 2021, meaning security seeds generated during that period may remain compromised. In the broader market context, market data shows the Federal Reserve held interest rates at 3.75% following its July 29, 2026 decision, maintaining a complex environment for high-risk assets.

Investors and Coldcard users should closely monitor security advisories from Coinkite, as firmware updates do not retroactively repair previously generated seeds. Furthermore, global sentiment indicators such as the US CB Consumer Confidence, which printed at 90.8 on July 28, 2026, will be critical in assessing how such security failures impact retail risk appetite.