# VikBooking Hotel Booking Engine & PMS <= 1.8.16 - Unauthenticated Stored Cross-Site Scripting via Pre-Check-in Guest Fields

- **ID:** WPSEC-2026-1406
- **Plugin:** VikBooking Hotel Booking Engine & PMS (`vikbooking`), https://wordpress.org/plugins/vikbooking/
- **Affected versions:** all versions before 1.8.17
- **Fixed in:** 1.8.17 (Update to 1.8.17 or later.)
- **Severity:** Medium 5.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Low, affected versions None seen (as of 2026-10-21)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/vikbooking
- **Fix released:** 2026-10-20
- **Published:** 2026-10-21
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1406/

## Description

The VikBooking Hotel Booking Engine & PMS plugin for WordPress is vulnerable to Stored Cross-Site Scripting via file-type guest fields submitted through the front-end pre-check-in form in all versions up to, and including, 1.8.16, due to insufficient input sanitization and output escaping. The storeprecheckin task stores the raw guest values, and the admin booking check-in view prints them without escaping into a hidden input's value attribute. This makes it possible for unauthenticated attackers who hold a confirmed booking to inject arbitrary web scripts that execute when an administrator opens the booking check-in page.

## References

- https://wpsec.com/vuln/WPSEC-2026-1406/
- https://plugins.svn.wordpress.org/vikbooking/tags/1.8.17/
- https://wordpress.org/plugins/vikbooking/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1406/

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.