{"id":"CVE-2019-18224","title":"idn2_to_ascii_4i in lib/lookup.c in GNU libidn2 before 2.1.1 has a heap-based buffer overflow via a long domain string.","summary":"idn2_to_ascii_4i in lib/lookup.c in GNU libidn2 before 2.1.1 has a heap-based buffer overflow via a long domain string.","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-787","CWE-122"],"vendor":"gnu","product":"libidn2","affected":["libidn2 < 2.1.1"],"patched":["libidn2 2.1.1"],"published":"2019-10-21","updated":"2026-10-14","sourceUpdated":"2026-10-14T07:16:49.913","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2019-18224","references":[{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00008.html","label":"cve@mitre.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00009.html","label":"cve@mitre.org"},{"url":"https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=12420","label":"cve@mitre.org"},{"url":"https://github.com/libidn/libidn2/commit/e4d1558aa2c1c04a05066ee8600f37603890ba8c","label":"cve@mitre.org"},{"url":"https://github.com/libidn/libidn2/compare/libidn2-2.1.0...libidn2-2.1.1","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JDQVQ2XPV5BTZUFINT7AFJSKNNBVURNJ/","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MINU5RKDFE6TKAFY5DRFN3WSFDS4DYVS/","label":"cve@mitre.org"},{"url":"https://seclists.org/bugtraq/2020/Feb/4","label":"cve@mitre.org"},{"url":"https://security.gentoo.org/glsa/202003-63","label":"cve@mitre.org"},{"url":"https://usn.ubuntu.com/4168-1/","label":"cve@mitre.org"},{"url":"https://www.debian.org/security/2020/dsa-4613","label":"cve@mitre.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00008.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00009.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=12420","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/libidn/libidn2/commit/e4d1558aa2c1c04a05066ee8600f37603890ba8c","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/libidn/libidn2/compare/libidn2-2.1.0...libidn2-2.1.1","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JDQVQ2XPV5BTZUFINT7AFJSKNNBVURNJ/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MINU5RKDFE6TKAFY5DRFN3WSFDS4DYVS/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://seclists.org/bugtraq/2020/Feb/4","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202003-63","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/4168-1/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2020/dsa-4613","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2019/cve-2019-18224.json"},{"url":"https://access.redhat.com/security/cve/CVE-2019-18224"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1764780"},{"url":"https://www.cve.org/CVERecord?id=CVE-2019-18224"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-18224"},{"url":"https://access.redhat.com/errata/RHBA-2019:3621"}],"tags":["nvd","csaf","vex","red-hat","score-dispute"],"epss":0.03708,"epssPercentile":0.89513,"ingestedAt":"2026-10-14T07:21:04.821Z","scores":{"nvd":9.8,"vendor":5.6},"slug":"CVE-2019-18224","body":"## Overview\n\nidn2_to_ascii_4i in lib/lookup.c in GNU libidn2 before 2.1.1 has a heap-based buffer overflow via a long domain string.\n\n## Affected\n\n- `libidn2 < 2.1.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `libidn2 2.1.1`\n\n## Vendor advisories\n\n- **RHBA-2019:3621** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux BaseOS (v. 8), Red Hat CodeReady Linux Builder (v. 8) · released 2019-11-05 · [advisory](https://access.redhat.com/errata/RHBA-2019:3621)","depth":"midnight","depthScore":55,"depthScoreParts":{"impact":53.9,"likelihood":0.7,"exploitation":0,"ransomware":0},"changes":[]}