{"id":"CVE-2021-26539","aliases":["GHSA-rjqq-98f6-6j3r"],"url":"https://o3.security/vulnerability/CVE-2021-26539","summary":"Improper Input Validation in sanitize-html","details":"Apostrophe Technologies sanitize-html before 2.3.1 does not properly handle internationalized domain name (IDN) which could allow an attacker to bypass hostname whitelist validation set by the \"allowedIframeHostnames\" option.","published":"2021-02-08T17:15:13.673Z","modified":"2026-08-07T15:15:25.018499Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"npm","name":"sanitize-html","fixedVersion":"2.3.1"}],"fix":{"url":"https://github.com/apostrophecms/sanitize-html/pull/458","label":"apostrophecms/sanitize-html#458"},"references":[{"type":"ADVISORY","url":"https://github.com/apostrophecms/sanitize-html/blob/main/CHANGELOG.md#231-2021-01-22"},{"type":"FIX","url":"https://github.com/apostrophecms/sanitize-html/pull/458"},{"type":"EVIDENCE","url":"https://advisory.checkmarx.net/advisory/CX-2021-4308"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T15:15:25.018499Z"}}