{"id":"CVE-2018-8777","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-8777","generatedAt":"2026-10-28T19:19:35.282Z","title":"In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, an attacker can pass a large HTTP request with a crafted header to WEBrick server or a crafted body to WEBrick server/handler and cause a denial of…","description":"In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, an attacker can pass a large HTTP request with a crafted header to WEBrick server or a crafted body to WEBrick server/handler and cause a denial of service (memory consumption).","published":"2018-04-03T22:29:01.000Z","lastModified":"2026-06-17T02:05:22.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":7.5,"severity":"HIGH","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-400"],"affected":["ruby-lang/ruby","debian/debian linux","canonical/ubuntu linux","redhat/enterprise linux"],"epss":{"score":0.04458,"percentile":0.91382,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (4.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html","source":"cve@mitre.org"},{"url":"http://www.securityfocus.com/bid/103683","tags":["Third Party Advisory","VDB Entry"],"source":"cve@mitre.org"},{"url":"http://www.securitytracker.com/id/1042004","tags":["Third Party Advisory","VDB Entry"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2018:3729","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2018:3730","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2018:3731","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2028","source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2020:0542","source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2020:0591","source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2020:0663","source":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2018/04/msg00023.html","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2018/04/msg00024.html","tags":["Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html","tags":["Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://usn.ubuntu.com/3685-1/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.debian.org/security/2018/dsa-4259","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/large-request-dos-in-webrick-cve-2018-8777/","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-2-10-released/","tags":["Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-3-7-released/","tags":["Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-4-4-released/","tags":["Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-5-1-released/","tags":["Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securityfocus.com/bid/103683","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1042004","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2018:3729","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2018:3730","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2018:3731","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2028","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2020:0542","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2020:0591","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2020:0663","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2018/04/msg00023.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2018/04/msg00024.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/3685-1/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2018/dsa-4259","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/large-request-dos-in-webrick-cve-2018-8777/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-2-10-released/","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-3-7-released/","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-4-4-released/","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.ruby-lang.org/en/news/2018/03/28/ruby-2-5-1-released/","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-8777","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}