{"id":"CVE-2019-17023","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-17023","generatedAt":"2026-10-27T23:36:20.727Z","title":"This vulnerability affects Firefox < 72.","description":"After a HelloRetryRequest has been sent, the client may negotiate a lower protocol that TLS 1.3, resulting in an invalid state transition in the TLS State Machine. If the client gets into this state, incoming Application Data records will be ignored. This vulnerability affects Firefox < 72.","published":"2020-01-08T22:15:13.000Z","lastModified":"2026-06-17T02:23:11.000Z","status":"Modified","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N"},"cwe":["CWE-287"],"affected":["mozilla/firefox","canonical/ubuntu linux","debian/debian linux"],"epss":{"score":0.0134,"percentile":0.71115,"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":"low","text":"Lower severity and a low EPSS score (1.34%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1590001","tags":["Issue Tracking","Permissions Required"],"source":"security@mozilla.org"},{"url":"https://usn.ubuntu.com/4234-1/","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://usn.ubuntu.com/4397-1/","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://www.debian.org/security/2020/dsa-4726","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2020-01/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1590001","tags":["Issue Tracking","Permissions Required"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/4234-1/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/4397-1/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2020/dsa-4726","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2020-01/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-17023","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."}