# User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder <= 5.3.1 - Unauthenticated Arbitrary Shortcode Execution via 'ur_error' and 'info' Parameters

- **ID:** WPSEC-2026-2711
- **Plugin:** User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder (`user-registration`), https://wordpress.org/plugins/user-registration/
- **Affected versions:** all versions before 5.3.2
- **Fixed in:** 5.3.2 (Update to 5.3.2 or later.)
- **Severity:** High 7.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L)
- **Weakness:** CWE-94
- **Usage among sites WPSec scans:** plugin Medium, affected versions Medium (as of 2026-11-07)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/user-registration
- **Fix released:** 2026-11-06
- **Published:** 2026-11-07
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2711/

## Description

The User Registration & Membership plugin for WordPress is vulnerable to Arbitrary Shortcode Execution via the 'ur_error' and 'info' query parameters in all versions up to, and including, 5.3.1, due to the plugin adding these values to front-end login notices and the membership thank-you page with their square brackets intact. That output is then passed through do_shortcode(): the login preview injects it into the_content before shortcodes run, and the plugin's Login Form, My Account and Thank You blocks are rendered before the_content runs shortcodes. Any visitor could also turn on the login preview just by adding 'ur_login_preview' to a URL. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.

## References

- https://wpsec.com/vuln/WPSEC-2026-2711/
- https://plugins.svn.wordpress.org/user-registration/tags/5.3.2/
- https://wordpress.org/plugins/user-registration/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2711/

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.