Vulnerability · Published Aug 15, 2026 · Assigned by Wordfence

CVE-2026-8840Booking calendar, Appointment Booking System <= 3.2.36 - Missing Authorization to Unauthenticated Arbitrary Modification via wpdevart_payment AJAX Action

Medium 5.3

In plain English

A medium-severity missing authorization in Booking calendar, Appointment Booking System from wpdevart. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.5%top 54.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The Booking calendar, Appointment Booking System plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 3.2.36. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for unauthenticated attackers to mark arbitrary reservations as paid or completed, cancel legitimate payments, auto-approve reservations, and trigger transactional booking emails by writing attacker-supplied payment status and transaction data directly into the payments table. The auto-approval of reservations is only triggered when the 'enable_psuccess_approval' site option is enabled, but payment status manipulation and email dispatch are exploitable regardless of that setting.

Affected products (as reported)

Vendor	Product	Versions
wpdevart	Booking calendar, Appointment Booking System	0 – through 3.2.36

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

In plain English

Official description

Affected products (as reported)

References