{"id":"CVE-2019-12290","title":"GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels","summary":"GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels. This makes it possible in some circumstances for one domain to impersonate another. By creating a malic…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","cwe":["CWE-20"],"vendor":"gnu","product":"libidn2","affected":["libidn2 < 2.2.0"],"patched":["libidn2 2.2.0"],"published":"2019-10-22","updated":"2026-10-14","sourceUpdated":"2026-10-14T07:16:45.200","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2019-12290","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://gitlab.com/libidn/libidn2/commit/241e8f486134793cb0f4a5b0e5817a97883401f5","label":"cve@mitre.org"},{"url":"https://gitlab.com/libidn/libidn2/commit/614117ef6e4c60e1950d742e3edf0a0ef8d389de","label":"cve@mitre.org"},{"url":"https://gitlab.com/libidn/libidn2/merge_requests/71","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFT76Y7OSGPZV3EBEHD6ISVUM3DLARM/","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KXDKYWFV6N2HHVSE67FFDM7G3FEL2ZNE/","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ONG3GJRRJO35COPGVJXXSZLU4J5Y42AT/","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RSI4TI2JTQWQ3YEUX5X36GTVGKO4QKZ5/","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U6ZXL2RDNQRAHCMKWPOMJFKYJ344X4HL/","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":"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://gitlab.com/libidn/libidn2/commit/241e8f486134793cb0f4a5b0e5817a97883401f5","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://gitlab.com/libidn/libidn2/commit/614117ef6e4c60e1950d742e3edf0a0ef8d389de","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://gitlab.com/libidn/libidn2/merge_requests/71","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFT76Y7OSGPZV3EBEHD6ISVUM3DLARM/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KXDKYWFV6N2HHVSE67FFDM7G3FEL2ZNE/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ONG3GJRRJO35COPGVJXXSZLU4J5Y42AT/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RSI4TI2JTQWQ3YEUX5X36GTVGKO4QKZ5/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U6ZXL2RDNQRAHCMKWPOMJFKYJ344X4HL/","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://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd"],"epss":0.03106,"epssPercentile":0.87454,"ingestedAt":"2026-10-14T07:21:04.822Z","slug":"CVE-2019-12290","body":"## Overview\n\nGNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels. This makes it possible in some circumstances for one domain to impersonate another. By creating a malicious domain that matches a target domain except for the inclusion of certain punycoded Unicode characters (that would be discarded when converted first to a Unicode label and then back to an ASCII label), arbitrary domains can be impersonated.\n\n## Affected\n\n- `libidn2 < 2.2.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `libidn2 2.2.0`","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.3,"likelihood":0.6,"exploitation":0,"ransomware":0},"changes":[]}