CVE-2026-8840 Missing authorization in Booking calendar, Appointment Booking System
Unauthenticated attackers can modify reservation payment statuses and trigger emails due to missing authorization checks in the Booking calendar plugin.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-8840?
CVE-2026-8840 is a medium-severity missing authorization vulnerability in wpdevart Booking calendar, Appointment Booking System, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-862
Which versions are affected by CVE-2026-8840?
How do I fix CVE-2026-8840?
No fix has been published for CVE-2026-8840 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-8840 being exploited?
There is no known exploitation of CVE-2026-8840 in the wild and no public exploit code.
Sources
Also known as GHSA-g8cr-48gj-g988.