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

- **ID:** WPSEC-2026-1562
- **Plugin:** Kadence Blocks — Page Builder Toolkit for Gutenberg Editor (`kadence-blocks`), https://wordpress.org/plugins/kadence-blocks/
- **Affected versions:** all versions 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-2026-1562/

## Description

The Kadence Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Simple Lightbox script used by the legacy Advanced Button video popup in all versions up to, and including, 3.8.0.1, due to the link URL and the caption (taken from the link's title attribute or a nearby figcaption) being concatenated into HTML and inserted via innerHTML without escaping. 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 and opens the lightbox.

## References

- https://wpsec.com/vuln/WPSEC-2026-1562/
- 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-2026-1562/

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.