CVE-2026-45270: CI4MS: Stored XSS in Pages Module Content via Broken html_purify Validation Rule

The Pages backend module registers the html_purify validation rule on language-keyed page content but persists the raw, un-purified POST value into the database. The public renderer for pages (Home::index() → app/Views/templates/default/pages.php) emits $pageInfo->content without esc(), yielding stored XSS that fires for every public visitor of the affected page — including administrators. Because pages may be promoted to the site home page, the payload can be served at / and reach every visitor of the site.