# Pie Register <= 3.8.4.15 - Authenticated (Contributor+) Missing Authorization to Invitation Code Update

- **ID:** WPSEC-2026-2122
- **Plugin:** Pie Register – User Registration, Profiles & Content Restriction (`pie-register`), https://wordpress.org/plugins/pie-register/
- **Affected versions:** all versions before 3.8.4.16
- **Fixed in:** 3.8.4.16 (Update to 3.8.4.16 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-862
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-30)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/pie-register
- **Fix released:** 2026-10-29
- **Published:** 2026-10-30
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2122/

## Description

The pie-register plugin for WordPress is vulnerable to unauthorized modification of data via the pireg_update_invitation_code AJAX action in all versions up to, and including, 3.8.4.15. This is due to a missing capability check in the pireg_update_invitation_code_cb_url() function, which only verified the 'pieregister_front_admin' nonce, and that nonce was also printed on the post editing screens. This makes it possible for authenticated attackers, with Contributor-level access and above, to modify the name, description and usage limit of arbitrary invitation codes.

## References

- https://wpsec.com/vuln/WPSEC-2026-2122/
- https://plugins.svn.wordpress.org/pie-register/tags/3.8.4.16/
- https://wordpress.org/plugins/pie-register/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2122/

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.