Threats Tagged 'cve-2026-66370'

CVE-2026-66370 is an open redirect vulnerability in the html_sanitize_ex HTML5 scrubber by rrrene. It allows an unauthenticated remote attacker to manipulate form input elements to redirect form submissions to an attacker-controlled external URL. The vulnerability arises because the sanitizer does not validate the scheme of the form and formaction attributes on input elements, allowing cross-origin URLs to persist after sanitization. No script execution is possible, and the attacker cannot inject new forms, only retarget existing forms on the page. This affects versions from 0.3.1 up to but not including 1.5.3, including 1.5.0-rc.0.

URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to retarget a form already on the rendering page and receive whatever the victim submits, including credentials, via the form and formaction attributes on an <input> element in sanitized HTML. HTML's form attribute associates an input with any form on the page by its id even when the input sits outside that form, and formaction on a submit control overrides the owning form's action. Neither attribute receives a scheme check, so an absolute cross-origin URL survives sanitizing. No script executes. The scrubber allows neither form nor button, so the attacker cannot introduce a form of their own and the rendering page must already contain a form carrying an id. This issue affects html_sanitize_ex: from 0.3.1 before 1.4.5 and from 1.5.0-rc.0 before 1.5.3.