CVE-2026-4561

Description

The MC4WP: Mailchimp for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the form response message post meta fields (e.g., 'text_subscribed', 'text_error') in all versions up to, and including, 4.12.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

References

• https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/trunk/includes/forms/class-form-element.php#L116
• https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/trunk/includes/forms/class-form-manager.php#L104
• https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/trunk/includes/forms/class-form.php#L295
• https://plugins.trac.wordpress.org/changeset/3491781/
• https://www.wordfence.com/threat-intel/vulnerabilities/id/641b739d-f888-4327-b1c5-c95de39ee011?source=cve