# Nexter Blocks <= 5.0.7 - Authenticated (Contributor+) Stored Cross-Site Scripting via Smooth Scroll and Post Image Data Attributes

- **ID:** WPSEC-2026-1580
- **Plugin:** Nexter Blocks – Gutenberg Blocks, Page Builder & AI Website Builder (`the-plus-addons-for-block-editor`), https://wordpress.org/plugins/the-plus-addons-for-block-editor/
- **Affected versions:** all versions before 5.0.8
- **Fixed in:** 5.0.8 (Update to 5.0.8 or later.)
- **Severity:** Medium 6.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-24)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/the-plus-addons-for-block-editor
- **Fix released:** 2026-10-23
- **Published:** 2026-10-24
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1580/

## Description

The Nexter Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Smooth Scroll and Post Image block attributes in all versions up to, and including, 5.0.7, due to insufficient output escaping. JSON-encoded attribute values, such as the Smooth Scroll easing settings and the Post Image block ID, were written into single-quoted HTML data attributes without encoding quotes. 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.

## References

- https://wpsec.com/vuln/WPSEC-2026-1580/
- https://plugins.svn.wordpress.org/the-plus-addons-for-block-editor/tags/5.0.8/
- https://wordpress.org/plugins/the-plus-addons-for-block-editor/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1580/

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.