# SchemaEngine AI – AI Schema Markup, Reviews & Rich Snippets for SEO <= 3.1.1 - Unauthenticated Denial of Service via 'max_page' Parameter

- **ID:** WPSEC-2026-0976
- **Plugin:** SchemaEngine AI – AI Schema Markup, Reviews & Rich Snippets for SEO (`review-schema`), https://wordpress.org/plugins/review-schema/
- **Affected versions:** all versions before 3.1.2
- **Fixed in:** 3.1.2 (Update to 3.1.2 or later.)
- **Severity:** Medium 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
- **Weakness:** CWE-400
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-15)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/review-schema
- **Fix released:** 2026-10-14
- **Published:** 2026-10-15
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0976/

## Description

The SchemaEngine AI – AI Schema Markup, Reviews & Rich Snippets for SEO plugin for WordPress is vulnerable to Denial of Service via the 'max_page' parameter of the rtrs_pagination AJAX action in all versions up to, and including, 3.1.1. This is due to the handler, which is registered for unauthenticated users, using the client-supplied page count without any upper bound when no sort order is given and passing it to paginate_links(), which loops once for every page. This makes it possible for unauthenticated attackers, using the nonce printed on any front-end page with reviews, to send requests that each keep a PHP worker busy until the execution time limit, consuming server resources and degrading site availability.

## References

- https://wpsec.com/vuln/WPSEC-2026-0976/
- https://plugins.svn.wordpress.org/review-schema/tags/3.1.2/
- https://wordpress.org/plugins/review-schema/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0976/

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.