CVE-2026-15149 in WP Hotel Booking Plugin
Summary
by MITRE • 08/07/2026
The WP Hotel Booking WordPress plugin before 2.3.3 does not ensure that room quantities and the resulting order total are non-negative when placing a booking, and relies on client-controlled cart data, allowing unauthenticated users to create confirmed reservations for free or at an arbitrarily reduced price.
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Analysis
by VulDB Data Team • 08/07/2026
The vulnerability exists within the WP Hotel Booking WordPress plugin version 2.3.2 and earlier, where the system fails to properly validate input parameters during the booking process. This flaw stems from inadequate server-side validation of cart data that is submitted by clients, creating a critical security gap that allows malicious actors to manipulate room quantities and order totals. The plugin's design relies heavily on client-controlled data without sufficient sanitization or verification mechanisms, enabling attackers to submit negative values or zero quantities that bypass normal pricing calculations. This represents a classic example of insufficient input validation where the system trusts user-supplied data without proper authorization checks or mathematical validation.
The technical implementation of this vulnerability allows unauthenticated users to exploit the booking system by manipulating the quantity parameters in their cart submissions. When a user attempts to book rooms, the plugin accepts and processes these values without verifying that they represent legitimate positive numbers. Attackers can submit negative room quantities which, when processed through the payment calculation logic, result in negative order totals or zero-priced bookings. This occurs because the system does not implement proper mathematical validation to ensure that all numeric values remain within expected ranges, specifically failing to check for non-negative constraints on room counts and associated pricing calculations.
The operational impact of this vulnerability is severe as it enables unauthorized free bookings or arbitrarily reduced price reservations without any authentication or authorization checks. An attacker can exploit this flaw to create confirmed reservations for free rooms or at prices significantly below the actual value, potentially resulting in substantial financial losses for the hotel or booking service provider. This vulnerability directly violates several security principles including input validation, access control, and data integrity. The flaw allows attackers to bypass normal pricing mechanisms and could be exploited at scale to cause significant revenue loss while maintaining persistent unauthorized access to the booking system.
Organizations should implement immediate mitigations including updating to WP Hotel Booking version 2.3.3 or later, which contains proper input validation fixes. Server-side validation must be strengthened to ensure all numeric inputs are properly sanitized and checked for non-negative values before processing payment calculations. The system should enforce strict parameter validation that rejects any negative quantities or invalid numerical inputs during the booking process. Additionally, implementing proper access controls and authentication checks would prevent unauthenticated users from initiating bookings altogether, though this vulnerability specifically affects the pre-authentication validation phase. Security monitoring should be enhanced to detect unusual booking patterns that might indicate exploitation attempts, while following established security frameworks such as CWE-191 for integer underflow/overflow vulnerabilities and ATT&CK technique T1078 for valid accounts abuse. The fix should also include logging all booking attempts with detailed parameter information to enable forensic analysis and prevent future exploitation of similar input validation weaknesses.
This vulnerability demonstrates the critical importance of server-side validation in web applications, particularly in e-commerce and reservation systems where financial transactions occur. The flaw represents a failure to implement proper defense-in-depth measures that should protect against malicious input manipulation at multiple layers of the application stack. Organizations implementing similar booking or reservation systems must ensure comprehensive input validation is enforced before any business logic processing occurs, as client-side controls alone cannot provide adequate security protection. The vulnerability also highlights the need for regular security audits and timely patch management to prevent exploitation of known flaws that could be easily remediated through proper code review and testing procedures.