CVE-2026-109989: Themify Popup <= 1.4.7 - Authenticated (Author+) Stored Cross-Site Scripting via 'popup_width_unit' Parameter

Q: Who can exploit this issue?

An attacker must be authenticated to WordPress with an Author-level account or higher. They can use the popup_width_unit parameter to store injected script content.

Q: When does the injected script execute?

The stored script executes when a user accesses a page containing the attacker-injected content. The issue can therefore affect other users who view the modified page.

Q: Which versions are affected?

All Themify Popup versions through 1.4.7, including version 1.4.7, are affected.

Published Oct 17, 2026

Updated

The Themify Popup plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'popupwidthunit' parameter in all versions up to, and including, 1.4.7 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.

Affected Software

1 affected component

Themify Themify Popup<=1.4.7

Event History

Oct 17, 2026

CVE Published

via MITRE·03:43 AM

Data Sourced

via MITRE·03:43 AM

DescriptionSeverityWeakness

Frequently Asked Questions

Who can exploit this issue?

An attacker must be authenticated to WordPress with an Author-level account or higher. They can use the popup_width_unit parameter to store injected script content.

When does the injected script execute?

The stored script executes when a user accesses a page containing the attacker-injected content. The issue can therefore affect other users who view the modified page.

Which versions are affected?