# Event Tickets and Registration <= 5.30.0.1 - Authenticated (Subscriber+) Missing Authorization to Attendee QR Check-In Status Modification

- **ID:** WPSEC-2026-0521
- **Plugin:** Event Tickets and Registration (`event-tickets`), https://wordpress.org/plugins/event-tickets/
- **Affected versions:** from 5.7.0 before 5.30.0.2
- **Fixed in:** 5.30.0.2 (Update to 5.30.0.2 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 Medium, affected versions Medium (as of 2026-10-07)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/event-tickets
- **Fix released:** 2026-10-06
- **Published:** 2026-10-07
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0521/

## Description

The Event Tickets and Registration plugin for WordPress is vulnerable to unauthorized modification of data in versions 5.7.0 to 5.30.0.1 due to a missing capability check in the QR check-in admin notice, which set the '_tribe_qr_status' meta on any post ID supplied in the 'qr_checked_in' query parameter. This makes it possible for authenticated attackers, with Subscriber-level access and above, to flag arbitrary attendees as already checked in by QR code by loading any admin page with a crafted parameter, causing QR code check-in to reject those attendees' tickets.

## References

- https://wpsec.com/vuln/WPSEC-2026-0521/
- https://plugins.svn.wordpress.org/event-tickets/tags/5.30.0.2/
- https://wordpress.org/plugins/event-tickets/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0521/

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.