{"cve":"CVE-2021-26539","nvd":{"published":"2021-02-08T17:15:13.673","modified":"2026-06-17T03:43:27.283","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3},"cwes":[],"references":["https://advisory.checkmarx.net/advisory/CX-2021-4308","https://github.com/apostrophecms/sanitize-html/blob/main/CHANGELOG.md#231-2021-01-22","https://github.com/apostrophecms/sanitize-html/pull/458","https://advisory.checkmarx.net/advisory/CX-2021-4308","https://github.com/apostrophecms/sanitize-html/blob/main/CHANGELOG.md#231-2021-01-22"],"products":["apostrophecms:sanitize-html"],"source":"nvd","synced_at":"2026-10-19T21:14:10.479542811+00:00"},"epss":{"cve":"CVE-2021-26539","score":0.01953,"percentile":0.80254,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-rjqq-98f6-6j3r","url":"https://osv.dev/vulnerability/GHSA-rjqq-98f6-6j3r","summary":"Improper Input Validation in sanitize-html","modified":"2023-11-08T04:05:21.094678Z","packages":[{"ecosystem":"npm","name":"sanitize-html","purl":"pkg:npm/sanitize-html","ranges":["<2.3.1"],"fixed":["2.3.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}