# Nias course <= 1.3.3 - Cross-Site Request Forgery to Course Curriculum Overwrite via nias_spotplayer_sync AJAX Action

- **ID:** WPSEC-2026-2823
- **Plugin:** Nias Course Builder (`nias-course`), https://wordpress.org/plugins/nias-course/
- **Affected versions:** all versions before 2.0.0
- **Fixed in:** 2.0.0 (Update to 2.0.0 or later.)
- **Severity:** Medium 4.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N)
- **Weakness:** CWE-352
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-11-10)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/nias-course
- **Fix released:** 2026-11-09
- **Published:** 2026-11-10
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2823/

## Description

The Nias Course Builder plugin for WordPress is vulnerable to Cross-Site Request Forgery via the nias_spotplayer_sync AJAX action in all versions up to, and including, 1.3.3, due to missing nonce validation in the nias_spotplayer_sync_handler() function. This makes it possible for unauthenticated attackers to make the site fetch an attacker-chosen URL and replace a course's chapters and lessons with content parsed from that page, via a forged request, if they can trick a shop manager or administrator into performing an action such as clicking a link.

## References

- https://wpsec.com/vuln/WPSEC-2026-2823/
- https://plugins.svn.wordpress.org/nias-course/tags/2.0.0/
- https://wordpress.org/plugins/nias-course/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2823/

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.