VULNERABILITY INTELLIGENCE
CVE-2021-26540
CVSS score5.3 MEDIUM
EPSS probability1.77%
CISA KEVNot currently listed
Published2021-02-08
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Description
Apostrophe Technologies sanitize-html before 2.3.2 does not properly validate the hostnames set by the "allowedIframeHostnames" option when the "allowIframeRelativeUrls" is set to true, which allows attackers to bypass hostname whitelist for iframe element, related using an src value that starts with "/\\example.com".
Primary references
- cve@mitre.org — Exploit, Patch, Third Party Advisory
- cve@mitre.org — Release Notes, Third Party Advisory
- cve@mitre.org — Patch, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Exploit, Patch, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Release Notes, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory