# Nexter Blocks <= 5.0.7 - Authenticated (Contributor+) Stored Cross-Site Scripting via Countdown Block Expiry Redirect URL

- **ID:** WPSEC-2026-1578
- **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 4.9 (CVSS:3.1/AV:N/AC:H/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-2026-1578/

## Description

The Nexter Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Countdown block's expiry redirect URL in all versions up to, and including, 5.0.7, due to insufficient input sanitization. The redirect URL was passed unsanitized to a client-side redirect that runs when the countdown expires, which accepts javascript: URLs. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute when the countdown expires while a user is viewing an injected page.

## References

- https://wpsec.com/vuln/WPSEC-2026-1578/
- 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-2026-1578/

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.