CVE-2026-4081
Deferred Deferred - Pending Action
Stored XSS in ZeM STL WordPress Plugin

Publication date: 2026-06-02

Last updated on: 2026-06-02

Assigner: Wordfence

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.
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Meta Information
Published
2026-06-02
Last Modified
2026-06-02
Generated
2026-06-22
AI Q&A
2026-06-02
EPSS Evaluated
2026-06-21
NVD
CVE-2026-4081
EUVD
EUVD-2026-33885
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
zem_stl zem_stl to 1.0 (inc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
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Executive Summary

The ZeM STL plugin for WordPress has a Stored Cross-Site Scripting (XSS) vulnerability in its [zemstl] shortcode. This occurs because the plugin does not properly sanitize or escape user-supplied shortcode attributes such as 'url', 'color', and 'bgcolor'. These attributes are directly inserted into HTML without using escaping functions like esc_attr(), allowing attackers with Contributor-level access or higher to inject malicious scripts that execute when other users view the affected pages.

Impact Analysis

This vulnerability can allow authenticated attackers with Contributor-level access or above to inject arbitrary malicious scripts into pages. When other users visit these pages, the injected scripts execute in their browsers, potentially leading to theft of user credentials, session hijacking, defacement, or other malicious actions. This compromises the security and integrity of the affected WordPress site and its users.

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