CVE-2026-9643

Description

The WP Meta SEO plugin for WordPress is vulnerable to Unauthenticated Stored Cross-Site Scripting via the REQUEST_URI server variable in all versions up to, and including, 4.5.18. When the plugin-s `wpmsTemplateRedirect()` hook detects a 404, it concatenates `$_SERVER[-HTTP_HOST-]` with the raw `$_SERVER[-REQUEST_URI-]` and inserts that value verbatim into the `wp_wpms_links.link_url` column via `$wpdb->insert()`. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute whenever an administrator views the plugin-s 404 & Redirects admin page (`/wp-admin/admin.php?page=metaseo_broken_link`).