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CVE PROGRAM SOURCE RECORD2.3 Low

CVE-2026-66829

html_sanitize_ex HTML5 scrubber keeps attacker-supplied meta refresh, allowing forced cross-origin redirection

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

rrrene html_sanitize_ex

Default version status: unaffected

  • 0.3.1 to < 1.4.5affected
  • 1.5.0-rc.0 to < 1.5.3affected
pkg:hex/html_sanitize_ex

rrrene html_sanitize_ex

Default version status: unaffected

  • 8976d64ea0b77d26093a94a43ec48a3978e8d028 to < *affected
pkg:github/rrrene/html_sanitize_ex

References