CVE-2026-4081: Jhdscript Zem Stl

Medium severity, CVSS 6.4. EPSS: 0.4% chance of exploitation in the next 30 days.

The ZeM STL plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the [zemstl] shortcode in all versions up to and including 1.0. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes, specifically the 'url', 'color', and 'bgcolor' parameters. These attribute values are directly interpolated into HTML attribute context without being passed through esc_attr() or any other escaping function. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Affected products

• Jhdscript Zem Stl: up to and including 1.0

Published 2026-06-02. Last modified 2026-07-22.