Appointment Bookings for Zoom GoogleMeet and more – Wappointment <= 2.7.6 - Unauthenticated Insecure Direct Object Reference via Predictable 'edit_key' / 'appointmentkey' Parameter

5.3
Authorization Bypass Through User-Controlled Key
CVE CVE-2026-9188
CVSS 5.3 (Medium)
Publicly Published July 1, 2026
Last Updated July 2, 2026
Researcher davidfdzmorilla

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.

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Vulnerability Details for Appointment Bookings for Zoom GoogleMeet and more – Wappointment

Software Type Plugin
Software Slug wappointment (view on wordpress.org)
Patched? Yes
Remediation Update to version 2.7.7, or a newer patched version
Affected Version
  • <= 2.7.6
Patched Version
  • 2.7.7

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