CVE-2026-9188 Missing authorization in Appointment Bookings for Zoom GoogleMeet and more – Wappointment
Unauthenticated attackers can cancel or reschedule other users' appointments by predicting insecure direct object reference keys in the Wappointment 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-2026-9188?
CVE-2026-9188 is a medium-severity missing authorization vulnerability in Appointment Bookings for Zoom GoogleMeet and more – Wappointment, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The Appointment Bookings for Zoom GoogleMeet and more – Wappointment plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to and including 2.7.6 via the `appointmentkey` parameter due to the appointment `edit_key` — the sole authorization token consumed by `tryCancel()` — being generated as a predictable, unsalted MD5 hash of only `client_id` (a sequential integer), `start_at` (a publicly observable appointment timestamp), and `staff_id` (a small enumerable integer), with no secret salt or random component, and the unauthenticated cancellation and rescheduling REST endpoints performing no ownership or identity verification beyond matching this reconstructible key. This makes it possible for unauthenticated attackers to compute valid `edit_key` values for appointments belonging to other users and cancel or reschedule those appointments arbitrarily. Exploitation requires the `allow_cancellation` or `allow_rescheduling` setting to be enabled on the site, both of which are common configurations for active booking deployments; an attacker can obtain the inputs needed to reconstruct a victim's key by booking their own appointment to observe their sequential `client_id` and correlating publicly visible appointment times and enumerable staff identifiers.
Weakness: CWE-639
Which versions are affected by CVE-2026-9188?
How do I fix CVE-2026-9188?
No fix has been published for CVE-2026-9188 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-2026-9188 being exploited?
There is no known exploitation of CVE-2026-9188 in the wild and no public exploit code.
Sources
Also known as GHSA-x67v-h94m-3pj6.