# User Profile Builder <= 4.0.4 - Authenticated (Subscriber+) CAPTCHA Bypass via REST API and XML-RPC Comments

- **ID:** WPSEC-2026-1353
- **Plugin:** User Profile Builder – Beautiful User Registration Forms, User Profiles & User Role Editor (`profile-builder`), https://wordpress.org/plugins/profile-builder/
- **Affected versions:** all versions before 4.0.5
- **Fixed in:** 4.0.5 (Update to 4.0.5 or later.)
- **Severity:** Medium 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N)
- **Weakness:** CWE-693
- **Usage among sites WPSec scans:** plugin Medium, affected versions Medium (as of 2026-10-21)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/profile-builder
- **Fix released:** 2026-10-19
- **Published:** 2026-10-21
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1353/

## Description

The User Profile Builder plugin for WordPress is vulnerable to a CAPTCHA bypass on the default WordPress comments form in all versions up to, and including, 4.0.4. This is due to the reCAPTCHA and Turnstile checks in wppb_verify_recaptcha_default_wp_comments() and wppb_verify_turnstile_default_wp_comments() running only when the HTML comment form is submitted. When CAPTCHA protection for comments is enabled, this makes it possible for authenticated attackers with Subscriber-level access and above to post comments through the REST API or XML-RPC without solving the CAPTCHA. Unauthenticated attackers can do the same on sites that allow anonymous API comments.

## References

- https://wpsec.com/vuln/WPSEC-2026-1353/
- https://plugins.svn.wordpress.org/profile-builder/tags/4.0.5/
- https://wordpress.org/plugins/profile-builder/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1353/

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.