--- title: Critical UniFi OS bug lets hackers gain root without... description: Three chained vulnerabilities in Ubiquiti UniFi OS Server (CVE-2026-34908, CVE-2026-34909, CVE-2026-34910) allow unauthenticated remote code execution with... canonical: https://daily.dev/posts/critical-unifi-os-bug-lets-hackers-gain-root-without-authentication-wfqtinglo twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Critical UniFi OS bug lets hackers gain root without authentication | daily.dev og:description: Three chained vulnerabilities in Ubiquiti UniFi OS Server (CVE-2026-34908, CVE-2026-34909, CVE-2026-34910) allow unauthenticated remote code execution with... og:url: https://daily.dev/posts/critical-unifi-os-bug-lets-hackers-gain-root-without-authentication-wfqtinglo og:image: https://api.daily.dev/og/posts/WfqtINGlo.png og:image:alt: Critical UniFi OS bug lets hackers gain root without authentication 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. # Critical UniFi OS bug lets hackers gain root without authentication **[BleepingComputer](https://daily.dev/sources/bleepingcomputer)** · 4 min read · 0 upvotes · 0 comments ## Summary Three chained vulnerabilities in Ubiquiti UniFi OS Server (CVE-2026-34908, CVE-2026-34909, CVE-2026-34910) allow unauthenticated remote code execution with root privileges. The attack exploits a mismatch between how UniFi OS validates raw request URIs versus how Nginx normalizes them, enabling authentication bypass. Combined with a path traversal and command injection flaw, attackers can reach a privileged service account with passwordless sudo access, making root escalation trivial. Bishop Fox researchers validated the full chain on UniFi OS Server 5.0.6 and released a free detection script on GitHub. Users should upgrade to UniFi OS Server 5.0.8 or later, and verify the system was not compromised before patching. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Ubiquiti warns of new max severity UniFi OS vulnerability](https://daily.dev/posts/ubiquiti-warns-of-new-max-severity-unifi-os-vulnerability-jcgjhlz0x) · BleepingComputer · 0 upvotes · 0 comments - [CISA warns of max severity Ubiquiti flaws exploited in attacks](https://daily.dev/posts/cisa-warns-of-max-severity-ubiquiti-flaws-exploited-in-attacks-28ufbhywd) · BleepingComputer · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security) [View this post on daily.dev](https://daily.dev/posts/critical-unifi-os-bug-lets-hackers-gain-root-without-authentication-wfqtinglo) ```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":"Critical UniFi OS bug lets hackers gain root without authentication","url":"https://daily.dev/posts/critical-unifi-os-bug-lets-hackers-gain-root-without-authentication-wfqtinglo","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/critical-unifi-os-bug-lets-hackers-gain-root-without-authentication-wfqtinglo"},"datePublished":"2026-06-08T15:53:30.589Z","dateModified":"2026-06-08T15:54:08.515Z","description":"Three chained vulnerabilities in Ubiquiti UniFi OS Server (CVE-2026-34908, CVE-2026-34909, CVE-2026-34910) allow unauthenticated remote code execution with...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/12914450f33b96d2891d1f49f7688641?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/12914450f33b96d2891d1f49f7688641?_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":0,"discussionUrl":"https://daily.dev/posts/critical-unifi-os-bug-lets-hackers-gain-root-without-authentication-wfqtinglo","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"security","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":"Critical UniFi OS bug lets hackers gain root without authentication"}]} ```