--- title: CISA: Hackers now exploit SolarWinds Serv-U flaw to... description: CISA has added CVE-2026-28318, a high-severity denial-of-service vulnerability in SolarWinds Serv-U file transfer software, to its Known Exploited... canonical: https://daily.dev/posts/cisa-hackers-now-exploit-solarwinds-serv-u-flaw-to-crash-servers-yw8vsu17o twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: CISA: Hackers now exploit SolarWinds Serv-U flaw to crash servers | daily.dev og:description: CISA has added CVE-2026-28318, a high-severity denial-of-service vulnerability in SolarWinds Serv-U file transfer software, to its Known Exploited... og:url: https://daily.dev/posts/cisa-hackers-now-exploit-solarwinds-serv-u-flaw-to-crash-servers-yw8vsu17o og:image: https://api.daily.dev/og/posts/yW8vSu17o.png og:image:alt: CISA: Hackers now exploit SolarWinds Serv-U flaw to crash servers 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. # CISA: Hackers now exploit SolarWinds Serv-U flaw to crash servers **[BleepingComputer](https://daily.dev/sources/bleepingcomputer)** · 3 min read · 0 upvotes · 0 comments ## Summary CISA has added CVE-2026-28318, a high-severity denial-of-service vulnerability in SolarWinds Serv-U file transfer software, to its Known Exploited Vulnerabilities Catalog after confirming active exploitation in the wild. The flaw allows unauthenticated remote attackers to crash Serv-U servers using specially crafted POST requests with Content-Encoding: deflate headers. SolarWinds released Serv-U 15.5.4 Hotfix 1 to address the issue and recommends admins who cannot patch immediately to restrict access to known IPs and block POST requests containing 'content-encoding'. Federal agencies have until June 19 to patch, and CISA urges private sector organizations to act quickly as well. Over 12,000 Serv-U servers are currently exposed online according to Shodan. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#security](https://daily.dev/tags/security) [View this post on daily.dev](https://daily.dev/posts/cisa-hackers-now-exploit-solarwinds-serv-u-flaw-to-crash-servers-yw8vsu17o) ```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":"CISA: Hackers now exploit SolarWinds Serv-U flaw to crash servers","url":"https://daily.dev/posts/cisa-hackers-now-exploit-solarwinds-serv-u-flaw-to-crash-servers-yw8vsu17o","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/cisa-hackers-now-exploit-solarwinds-serv-u-flaw-to-crash-servers-yw8vsu17o"},"datePublished":"2026-06-05T19:16:31.405Z","dateModified":"2026-06-05T19:16:55.905Z","description":"CISA has added CVE-2026-28318, a high-severity denial-of-service vulnerability in SolarWinds Serv-U file transfer software, to its Known Exploited...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/c02bf151d77fb4e3749d80651239e164?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/c02bf151d77fb4e3749d80651239e164?_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/cisa-hackers-now-exploit-solarwinds-serv-u-flaw-to-crash-servers-yw8vsu17o","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"security","timeRequired":"PT3M"} {"@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":"CISA: Hackers now exploit SolarWinds Serv-U flaw to crash servers"}]} ```