Threats Tagged 'cve-2026-66829'

CVE-2026-66829 is a low-severity open redirect vulnerability in the html_sanitize_ex library's HTML5 scrubber. It allows remote attackers to cause users to navigate to attacker-chosen sites via a <meta http-equiv="refresh"> element in sanitized HTML output. This is not a cross-site scripting issue, as script execution is not possible through this vector. The vulnerability affects versions from 0.3.1 up to but not including 1.5.3, including 1.5.0-rc.0. No official patch or fix is currently documented.

URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows a remote attacker to force visitors of a page to navigate to a site of the attacker's choosing via a <meta http-equiv="refresh"> element in sanitized HTML. HtmlSanitizeEx.html5/1 keeps attacker-supplied <meta> elements in its output. A meta element acts on the whole document rather than on the fragment it was embedded in, so it can also declare document-wide directives such as Content-Security-Policy. This is not cross-site scripting. Browsers do not navigate a meta refresh to a javascript: URL, so the uppercase JAVASCRIPT: filter bypass yields no script execution and none was demonstrated. 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.