--- title: Many old shim versions are still accepted by secure boot description: The CMU CERT Coordination Center has issued an advisory warning that many vulnerable versions of the shim bootloader — used to boot Linux on UEFI Secure Boot... canonical: https://daily.dev/posts/many-old-shim-versions-are-still-accepted-by-secure-boot-dbybqzma7 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Many old shim versions are still accepted by secure boot | daily.dev og:description: The CMU CERT Coordination Center has issued an advisory warning that many vulnerable versions of the shim bootloader — used to boot Linux on UEFI Secure Boot... og:url: https://daily.dev/posts/many-old-shim-versions-are-still-accepted-by-secure-boot-dbybqzma7 og:image: https://api.daily.dev/og/posts/dBYbQzMA7.png og:image:alt: Many old shim versions are still accepted by secure boot 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. # Many old shim versions are still accepted by secure boot **[LWN.net](https://daily.dev/sources/lwn)** · 1 min read · 0 upvotes · 0 comments ## Summary The CMU CERT Coordination Center has issued an advisory warning that many vulnerable versions of the shim bootloader — used to boot Linux on UEFI Secure Boot systems — were never added to the UEFI revocation list. An attacker with admin privileges or boot process access could exploit these old shim versions to bypass Secure Boot, execute arbitrary code before the OS loads, and achieve persistent platform compromise including loading unsigned or malicious kernel components that survive reboots and even OS reinstallation. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Schneier on Security](https://daily.dev/posts/schneier-on-security-gtentyiez) · Schneier on Security · 2 upvotes · 0 comments - [Windows and Linux users: The deadline to update Secure Boot keys is near](https://daily.dev/posts/windows-and-linux-users-the-deadline-to-update-secure-boot-keys-is-near-nvkg8wx89) · Ars Technica · 35 upvotes · 2 comments --- Tags: [#bootloader](https://daily.dev/tags/bootloader), [#linux](https://daily.dev/tags/linux), [#security](https://daily.dev/tags/security) [View this post on daily.dev](https://daily.dev/posts/many-old-shim-versions-are-still-accepted-by-secure-boot-dbybqzma7) ```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":"Many old shim versions are still accepted by secure boot","url":"https://daily.dev/posts/many-old-shim-versions-are-still-accepted-by-secure-boot-dbybqzma7","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/many-old-shim-versions-are-still-accepted-by-secure-boot-dbybqzma7"},"datePublished":"2026-07-15T12:52:40.420Z","dateModified":"2026-07-16T02:12:34.375Z","description":"The CMU CERT Coordination Center has issued an advisory warning that many vulnerable versions of the shim bootloader — used to boot Linux on UEFI Secure Boot...","image":"https://media.daily.dev/image/upload/s--CxzD6vbw--/f_auto/v1722860399/public/Placeholder%2005","thumbnailUrl":"https://media.daily.dev/image/upload/s--CxzD6vbw--/f_auto/v1722860399/public/Placeholder%2005","isAccessibleForFree":true,"articleSection":"LWN.net","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":"LWN.net","logo":"https://media.daily.dev/image/upload/s--4jjE7GIK--/f_auto,q_auto/v1774960833/logos/lwn?_a=BAMAMiWQ0","url":"https://daily.dev/sources/lwn"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/many-old-shim-versions-are-still-accepted-by-secure-boot-dbybqzma7","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"bootloader,linux,security","timeRequired":"PT1M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"LWN.net","item":"https://daily.dev/sources/lwn"},{"@type":"ListItem","position":3,"name":"Many old shim versions are still accepted by secure boot"}]} ```