{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.3.1"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "b77e1d9c3875b387589c864c796ce31a75e436a9"
            }
          ],
          "repo": "https://github.com/apostrophecms/sanitize-html",
          "type": "GIT"
        }
      ]
    }
  ],
  "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.",
  "id": "CVE-2021-26539",
  "modified": "2026-03-13T21:49:46.995906808Z",
  "published": "2021-02-08T17:15:13.673Z",
  "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"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}