{"id":"CVE-2020-11076","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-11076","generatedAt":"2026-10-27T22:25:21.198Z","title":"In Puma (RubyGem) before 4.3.4 and 3.12.5, an attacker could smuggle an HTTP response, by using an invalid transfer-encoding header.","description":"In Puma (RubyGem) before 4.3.4 and 3.12.5, an attacker could smuggle an HTTP response, by using an invalid transfer-encoding header. The problem has been fixed in Puma 3.12.5 and Puma 4.3.4.","published":"2020-05-22T15:15:11.000Z","lastModified":"2026-06-17T02:49:00.000Z","status":"Modified","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},"cwe":["CWE-444"],"affected":["puma/puma","fedoraproject/fedora","debian/debian linux"],"epss":{"score":0.04088,"percentile":0.90651,"date":"2026-10-26","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 (4.09%). 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/2020-07/msg00034.html","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00038.html","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/puma/puma/blob/master/History.md#434435-and-31253126--2020-05-22","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/puma/puma/commit/f24d5521295a2152c286abb0a45a1e1e2bd275bd","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/puma/puma/security/advisories/GHSA-x7jg-6pwg-fx5h","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.debian.org/debian-lts-announce/2020/10/msg00009.html","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SKIY5H67GJIGJL6SMFWFLUQQQR3EMVPR/","source":"security-advisories@github.com"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00034.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00038.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/puma/puma/blob/master/History.md#434435-and-31253126--2020-05-22","tags":["Release Notes"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/puma/puma/commit/f24d5521295a2152c286abb0a45a1e1e2bd275bd","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/puma/puma/security/advisories/GHSA-x7jg-6pwg-fx5h","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2020/10/msg00009.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SKIY5H67GJIGJL6SMFWFLUQQQR3EMVPR/","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-11076","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."}