CVE-2026-6498

What is known

The Five Star Restaurant Reservations plugin for WordPress is vulnerable to a payment bypass via PHP type juggling in versions up to, and including, 2.7.16 This is due to the valid_payment() function using a PHP loose comparison (==) between the attacker-controlled payment_id POST parameter and the booking's stripe_payment_intent_id property. When an unauthenticated attacker submits a request to the nopriv AJAX handler rtb_stripe_pmt_succeed before the Stripe payment intent has been created for a booking (i.e., before the JavaScript-triggered create_stripe_pmtIntnt() call has stored an intent ID in post meta), the stripe_payment_intent_id property on the booking object remains null. The comparison sanitize_text_field('') == null evaluates to TRUE in PHP loose comparison, causing the payment verification check to pass with zero actual payment. This makes it possible for unauthenticated attackers to mark any existing payment_pending booking as paid without completing a Stripe payment by submitting an empty payment_id parameter.

Business impact

Successful exploitation of CVE-2026-6498, a medium vulnerability (CVSS 5.3) affecting the affected product, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether the affected product is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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