CVE-2026-6498 [Medium] | Security Bypass in 'payment Id' Parameter Th…

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.03%	0.18%	+0.16%
2	2026-04-30	—	0.03%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.03%

0.18%

+0.16%

2026-04-30

—

0.03%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.3	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	3.9	1.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.3

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

3.9

1.4

[email protected]

Affected software / configurations for CVE-2026-6498

Vendor	Product	Version	Raw CPE
No affected products in dataset.

URL	Tags
https://plugins.trac.wordpress.org/browser/restaurant-reservations/tags/2.7.13/includes/PaymentGatewayStripe.class.php#L404
https://plugins.trac.wordpress.org/browser/restaurant-reservations/tags/2.7.13/includes/PaymentGatewayStripe.class.php#L458
https://plugins.trac.wordpress.org/browser/restaurant-reservations/trunk/includes/PaymentGatewayStripe.class.php#L404
https://plugins.trac.wordpress.org/browser/restaurant-reservations/trunk/includes/PaymentGatewayStripe.class.php#L458
https://plugins.trac.wordpress.org/changeset/3518833/restaurant-reservations/trunk/includes/PaymentGatewayStripe.class.php
https://plugins.trac.wordpress.org/changeset?old_path=%2Frestaurant-reservations/tags/2.7.16&new_path=%2Frestaurant-reservations/tags/2.7.17
https://www.wordfence.com/threat-intel/vulnerabilities/id/8ee08aac-7bcc-4809-a5aa-7b95ed736f19?source=cve

URL

CVE-2026-6498 | Five Star Restaurant Reservations <= 2.7.16 - Unauthenticated Payment Bypass via PHP Type Juggling in 'payment_id' Parameter

Exploit prediction scoring system (EPSS) score for CVE-2026-6498

Common vulnerability scoring system (CVSS) metrics for CVE-2026-6498

Weakness enumeration for CVE-2026-6498

GitHub Security Advisory for CVE-2026-6498

Affected software / configurations for CVE-2026-6498

References for CVE-2026-6498