CVE-2026-16986: Booking Package WordPress Auth Bypass Flaw

CVE-2026-16986 Overview

CVE-2026-16986 is a business logic vulnerability in The Booking Package WordPress plugin versions prior to 1.7.25. The plugin fails to validate the payment amount server-side against the stored service price. Instead, it derives the expected charge from attacker-controlled request parameters. An unauthenticated attacker can submit an arbitrary payment value and complete a booking for a fraction of the real service price. The flaw is categorized under CWE-284 (Improper Access Control) and affects the plugin's payment processing workflow.

Critical Impact
Unauthenticated attackers can book services at attacker-chosen prices, causing direct revenue loss for site operators using the plugin for paid reservations.

Affected Products

The Booking Package WordPress plugin versions before 1.7.25
WordPress sites using the plugin for paid service reservations
Merchant integrations relying on plugin-driven checkout pricing

Discovery Timeline

2026-08-26 - CVE-2026-16986 published to NVD
2026-08-26 - Last updated in NVD database

Technical Details for CVE-2026-16986

Vulnerability Analysis

The Booking Package plugin processes booking submissions from unauthenticated visitors. During checkout, the plugin calculates the amount to charge based on values supplied in the HTTP request rather than looking up the authoritative price from the server-side service record. This trust in client input turns a routine payment flow into a price-manipulation primitive.

A remote attacker can submit a booking request while overriding the price field or related pricing inputs. The plugin accepts the attacker-supplied figure and proceeds with a payment intent for that amount. The booking is then marked paid even though the transferred value is a small fraction of the true service cost. Because no authentication is required, exploitation scales trivially against any public booking form.

The impact is limited to integrity of transactional data (I:L) with no confidentiality or availability effect. However, repeated abuse produces cumulative financial loss and inconsistent booking records.

Root Cause

The plugin derives the expected charge from request parameters rather than from the stored service price in the database. Server-side validation that compares the submitted amount to the canonical service price is missing. This is a classic broken access control and business logic failure aligned with CWE-284.

Attack Vector

Exploitation occurs over the network against the public booking endpoint. The attacker intercepts or crafts the booking request, alters the price-bearing fields to an arbitrary lower value, and submits the form. The plugin issues a payment request for that value and finalizes the reservation. No user interaction, privileges, or prior access are required. Refer to the WPScan Vulnerability Report for additional technical detail.

Detection Methods for CVE-2026-16986

Indicators of Compromise

Completed bookings with payment amounts significantly below the configured service price
Payment gateway transactions whose captured amount does not match the stored price of the booked service
Anomalous HTTP POST requests to the plugin's booking endpoint containing non-standard price or total fields
Repeated bookings from the same IP or user agent shortly after plugin installation or upgrade

Detection Strategies

Reconcile every booking record against the authoritative service price table and flag mismatches
Compare payment processor settlement reports to expected revenue per service SKU
Inspect web server logs for booking submissions containing unexpected pricing parameters
Alert on modifications to request bodies bound for the booking submission handler

Monitoring Recommendations

Ingest WordPress access logs and payment gateway webhooks into a centralized analytics pipeline for correlation
Build dashboards that surface booking-to-price variance over rolling time windows
Monitor plugin version inventory across managed WordPress estates to identify hosts still on versions before 1.7.25

How to Mitigate CVE-2026-16986

Immediate Actions Required

Update The Booking Package plugin to version 1.7.25 or later on every WordPress instance
Audit recent bookings for underpaid transactions and initiate chargeback recovery or booking cancellation as appropriate
Temporarily disable public-facing booking forms if patching cannot be completed promptly

Patch Information

The vendor addressed the issue in version 1.7.25 of The Booking Package plugin. The patched release validates the payment amount server-side against the stored service price rather than trusting request-supplied values. Refer to the WPScan Vulnerability Report for advisory details.

Workarounds

Restrict access to the booking endpoint using a Web Application Firewall rule that rejects requests containing client-supplied price fields
Enforce server-side reconciliation between the payment gateway's captured amount and the canonical service price before confirming bookings
Require manual approval for bookings until the plugin is upgraded to a fixed version

bash

# Update The Booking Package plugin via WP-CLI
wp plugin update booking-package --version=1.7.25
wp plugin get booking-package --field=version