# Kadence Blocks <= 3.8.0.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via Advanced Button Video Popup Lightbox

- **ID:** WPSEC-2026-1561
- **Plugin:** Kadence Blocks — Page Builder Toolkit for Gutenberg Editor (`kadence-blocks`), https://wordpress.org/plugins/kadence-blocks/
- **Affected versions:** from 3.0.9 before 3.8.0.2
- **Fixed in:** 3.8.0.2 (Update to 3.8.0.2 or later.)
- **Severity:** Medium 5.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin High, affected versions High (as of 2026-10-23)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/kadence-blocks
- **Fix released:** 2026-10-22
- **Published:** 2026-10-23
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1561/

## Description

The Kadence Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Advanced Button block's video popup lightbox in all versions from 3.0.9 up to, and including, 3.8.0.1, due to insufficient sanitization of the lightbox title, description and media attributes of video popup links before they are rendered as HTML by GLightbox. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute when a user opens the video popup.

## References

- https://wpsec.com/vuln/WPSEC-2026-1561/
- https://plugins.svn.wordpress.org/kadence-blocks/tags/3.8.0.2/
- https://wordpress.org/plugins/kadence-blocks/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1561/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.