Vulnerability in SSL Zen — SSL Certificate Installer & HTTPS Redirects — CVE-2026-17577

What to do now

Update SSL Zen — SSL Certificate Installer & HTTPS Redirects to 4.7.43 or later.

Affected versions

• Everything up to and including 4.7.42

The SSL Zen plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'uri' (and 'host') parameters in versions up to, and including, 4.7.42. The ssl_zen_messages::getMessages() function builds the 'token_missmatch' message using base64_decode(sanitize_text_field($_REQUEST['uri'])) and (optionally) base64_decode(sanitize_text_field($_REQUEST['host'])). sanitize_text_field() cannot strip HTML/JavaScript that is hidden inside a base64-encoded blob, and the resulting decoded raw HTML is echoed unescaped by showMessage() . This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.

This description is reproduced verbatim from the public vulnerability record.

• https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.14/ssl_zen/classes/class.ssl_zen_admin.php#L863
• https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.14/ssl_zen/classes/class.ssl_zen_messages.php#L44
• https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.42/ssl_zen/classes/class.ssl_zen_admin.php#L863
• https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.42/ssl_zen/classes/class.ssl_zen_messages.php#L44
• https://plugins.trac.wordpress.org/changeset?reponame=&old=3701590%40ssl-zen&new=3701590%40ssl-zen
• https://www.wordfence.com/threat-intel/vulnerabilities/id/20816039-0b1c-420a-b5f4-b5370d0331da?source=cve

This page is compiled automatically from public databases. Accuracy is not guaranteed; confirm against the vendor advisory before acting.