CVE-2026-4081 ZeM STL <= 1.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
Authenticated attackers can inject arbitrary scripts via shortcode attributes, leading to code execution when users view affected pages.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-4081?
CVE-2026-4081 is a medium-severity cross-site scripting vulnerability in jhdscript ZeM STL, published on 2 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-4081?
How do I fix CVE-2026-4081?
No fix has been published for CVE-2026-4081 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-4081 being exploited?
There is no known exploitation of CVE-2026-4081 in the wild and no public exploit code.
Sources
Also known as GHSA-x84m-mwh2-95qm.