--- title: COLDCARD wallet RNG flaw likely linked to $88 million... description: A firmware flaw in COLDCARD hardware wallets caused the device to use a deterministic software random number generator (Yasmarang fallback) instead of the... canonical: https://daily.dev/posts/coldcard-wallet-rng-flaw-likely-linked-to-88-million-bitcoin-theft-oiit2xkec twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: COLDCARD wallet RNG flaw likely linked to $88 million Bitcoin theft | daily.dev og:description: A firmware flaw in COLDCARD hardware wallets caused the device to use a deterministic software random number generator (Yasmarang fallback) instead of the... og:url: https://daily.dev/posts/coldcard-wallet-rng-flaw-likely-linked-to-88-million-bitcoin-theft-oiit2xkec og:image: https://api.daily.dev/og/posts/Oiit2xkEc.png og:image:alt: COLDCARD wallet RNG flaw likely linked to $88 million Bitcoin theft og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # COLDCARD wallet RNG flaw likely linked to $88 million Bitcoin theft **[BleepingComputer](https://daily.dev/sources/bleepingcomputer)** · 4 min read · 6 upvotes · 1 comments ## Summary A firmware flaw in COLDCARD hardware wallets caused the device to use a deterministic software random number generator (Yasmarang fallback) instead of the STM32 hardware RNG. This allowed attackers to reconstruct wallet seeds offline, identify matching Bitcoin addresses on the blockchain, and drain funds. An estimated $88.6 million in Bitcoin was stolen from 4,585 addresses across multiple attack waves. Affected firmware spans Mk2/Mk3 versions 4.0.1–4.1.9 and various Mk4, Mk5, and Q versions before recent patches. Firmware updates are available but do not repair previously generated seeds — affected users must generate new seeds and migrate funds. Seeds supplemented with at least 50 dice rolls are not considered at risk from this flaw alone. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Community discussion Top comments from developers on daily.dev. **@taiwofrancis** · 0 upvotes > A tough lesson for the crypto community. --- Tags: [#crypto](https://daily.dev/tags/crypto), [#vulnerability](https://daily.dev/tags/vulnerability) [View this post on daily.dev](https://daily.dev/posts/coldcard-wallet-rng-flaw-likely-linked-to-88-million-bitcoin-theft-oiit2xkec) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"COLDCARD wallet RNG flaw likely linked to $88 million Bitcoin theft","url":"https://daily.dev/posts/coldcard-wallet-rng-flaw-likely-linked-to-88-million-bitcoin-theft-oiit2xkec","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/coldcard-wallet-rng-flaw-likely-linked-to-88-million-bitcoin-theft-oiit2xkec"},"datePublished":"2026-08-02T21:17:43.782Z","dateModified":"2026-08-05T00:51:48.969Z","description":"A firmware flaw in COLDCARD hardware wallets caused the device to use a deterministic software random number generator (Yasmarang fallback) instead of the...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/2b24f7406df12d8d260b95c03efc7c95?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/2b24f7406df12d8d260b95c03efc7c95?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"BleepingComputer","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"BleepingComputer","logo":"https://media.daily.dev/image/upload/s--as8nJ3qy--/f_auto,q_auto/v1774959951/logos/bleepingcomputer?_a=BAMAMiWQ0","url":"https://daily.dev/sources/bleepingcomputer"},"commentCount":1,"discussionUrl":"https://daily.dev/posts/coldcard-wallet-rng-flaw-likely-linked-to-88-million-bitcoin-theft-oiit2xkec","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":6},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":1}],"keywords":"crypto,vulnerability","timeRequired":"PT4M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"BleepingComputer","item":"https://daily.dev/sources/bleepingcomputer"},{"@type":"ListItem","position":3,"name":"COLDCARD wallet RNG flaw likely linked to $88 million Bitcoin theft"}]} {"@context":"https://schema.org","@type":"WebPage","@id":"https://daily.dev/posts/coldcard-wallet-rng-flaw-likely-linked-to-88-million-bitcoin-theft-oiit2xkec","comment":[{"@type":"Comment","text":"A tough lesson for the crypto community.","datePublished":"2026-08-03T10:59:56.424Z","url":"https://daily.dev/posts/Oiit2xkEc#c-EPY8qthQ9","author":{"@type":"Person","name":"Taiwo Francis Oguntade","url":"https://daily.dev/taiwofrancis","image":"https://media.daily.dev/image/upload/s--px3_Pvo4--/f_auto/v1785515368/avatars/avatar_FStpm3ZejUD3qGlEeoOUS?_a=BAMAMicg0"}}]} ```