CVE-2026-8840

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

2026-08-14 14:05
Raihan Adi Arba

Strategic Overview

Status
Unpatched
Affected Version
<= 3.2.36
CVSS
5.3Medium
Weakness type
CWE-862 · Missing Authorization
CVE
CVE-2026-8840
View all Booking calendar, Appointment Booking System vulnerabilities

At a glance

CVE-2026-8840 is a medium-severity Missing Authorization vulnerability in the Booking calendar, Appointment Booking System WordPress plugin, affecting versions <= 3.2.36. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed August 2026, reported by Raihan Adi Arba.

Vulnerability Overview

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.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-862: Missing Authorization

Booking calendar, Appointment Booking System <= 3.2.36 carries this weakness at enable_psuccess_approval, and reaching it takes no account at all. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.

Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. No fixed build of this plugin is recorded for Booking calendar, Appointment Booking System yet, so installs running <= 3.2.36 stay exposed until the vendor ships one.

Remediation

No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.

How does WordSec protect against this?

This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.

  • Login Security
  • Alerts

External References

Related records

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