CVE-2026-11901

medium

Description

The WP Hotel Booking plugin for WordPress is vulnerable to Insufficient Verification of Data Authenticity in all versions up to, and including, 2.3.1. This is due to the `web_hook_process_paypal_standard()` IPN handler selecting its PayPal validation endpoint from the attacker-controlled `$_REQUEST['test_ipn']` parameter, force-upgrading any `pending` transaction to `completed` when `test_ipn=1`, and omitting post-verification checks on `receiver_email`, `mc_currency`, and `txn_id` uniqueness after receiving a `VERIFIED` response from PayPal. This makes it possible for unauthenticated attackers to mark arbitrary hotel bookings as fully paid without submitting genuine payment to the merchant — either by routing IPN validation through PayPal's sandbox using a free sandbox account, or by replaying a previously verified IPN from a nominal payment to an attacker-controlled PayPal account. An attacker requires only a free PayPal sandbox account (or any PayPal account) to obtain a `VERIFIED` response; no site credentials or special configuration are needed.

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/191ec7ea-6ca7-4943-8709-f372ae5a81c7?source=cve

https://plugins.trac.wordpress.org/changeset?reponame=&old=3582839%40wp-hotel-booking&new=3582839%40wp-hotel-booking

https://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.1/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L253

https://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.1/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L194

https://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.1/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L186

https://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.1/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L173

https://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.0/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L253

https://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.0/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L194

https://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.0/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L186

https://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.0/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L173

Details

Source: Mitre, NVD

Published: 2026-07-11

Updated: 2026-07-11

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 5.3

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Severity: Medium