{"id":"CVE-2023-4236","url":"https://www.cyber-defence.io/tools/cve/CVE-2023-4236","generatedAt":"2026-10-27T23:56:35.651Z","title":"A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpectedly due to an assertion failure.","description":"A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.\nThis issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.","published":"2023-09-20T13:15:12.000Z","lastModified":"2026-06-17T06:37:23.000Z","status":"Modified","sourceIdentifier":"security-officer@isc.org","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:N/A:H"},"cwe":["CWE-617"],"affected":["isc/bind","fedoraproject/fedora","debian/debian linux","netapp/h300s firmware","netapp/h500s firmware","netapp/h700s firmware","netapp/h410s firmware","netapp/h410c firmware"],"epss":{"score":0.02207,"percentile":0.82452,"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 (2.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"http://www.openwall.com/lists/oss-security/2023/09/20/2","tags":["Mailing List","Third Party Advisory"],"source":"security-officer@isc.org"},{"url":"https://kb.isc.org/docs/cve-2023-4236","tags":["Vendor Advisory"],"source":"security-officer@isc.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IPJLLTJCSDJJII7IIZPLTBQNWP7MZH7F/","tags":["Mailing List"],"source":"security-officer@isc.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U35OARLQCPMVCBBPHWBXY5M6XJLD2TZ5/","tags":["Mailing List"],"source":"security-officer@isc.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VSK5V4W4OHPM3JTJGWAQD6CZW7SFD75B/","tags":["Mailing List","Third Party Advisory"],"source":"security-officer@isc.org"},{"url":"https://security.netapp.com/advisory/ntap-20231013-0004/","tags":["Third Party Advisory"],"source":"security-officer@isc.org"},{"url":"https://www.debian.org/security/2023/dsa-5504","tags":["Third Party Advisory"],"source":"security-officer@isc.org"},{"url":"http://www.openwall.com/lists/oss-security/2023/09/20/2","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://kb.isc.org/docs/cve-2023-4236","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IPJLLTJCSDJJII7IIZPLTBQNWP7MZH7F/","tags":["Mailing List"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U35OARLQCPMVCBBPHWBXY5M6XJLD2TZ5/","tags":["Mailing List"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VSK5V4W4OHPM3JTJGWAQD6CZW7SFD75B/","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20231013-0004/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2023/dsa-5504","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2023-4236","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."}