CVE-2026-9188 | Appointment Bookings for Zoom GoogleMeet and more – Wappointment <= 2.7.6 - Unauthenticated Insecure Direct Object Reference via Predictable 'edit_key' / 'appointmentkey' Parameter

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.

Published: 2026-07-02 Last update: 2026-07-02 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-9188 is rated Low Risk (28.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.30%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-9188

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-03 0.52% 0.30% -0.22%
2 2026-07-02 0.52%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-9188

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-9188

GitHub Security Advisory for CVE-2026-9188

GHSA-x67v-h94m-3pj6 · Severity: medium — The Appointment Bookings for Zoom GoogleMeet and more – Wappointment plugin for WordPress is...

Affected software / configurations for CVE-2026-9188

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-9188

URL Tags
https://plugins.trac.wordpress.org/browser/wappointment/tags/2.7.5/app/Models/Client.php#L39
https://plugins.trac.wordpress.org/browser/wappointment/tags/2.7.5/app/Services/AppointmentNew.php#L190
https://plugins.trac.wordpress.org/browser/wappointment/tags/2.7.5/app/Services/AppointmentNew.php#L347
https://plugins.trac.wordpress.org/browser/wappointment/tags/2.7.5/app/Services/AppointmentNew.php#L40
https://plugins.trac.wordpress.org/browser/wappointment/tags/2.7.6/app/Models/Client.php#L39
https://plugins.trac.wordpress.org/browser/wappointment/tags/2.7.6/app/Services/AppointmentNew.php#L190
https://plugins.trac.wordpress.org/browser/wappointment/tags/2.7.6/app/Services/AppointmentNew.php#L347
https://plugins.trac.wordpress.org/browser/wappointment/tags/2.7.6/app/Services/AppointmentNew.php#L40
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3546313%40wappointment&new=3546313%40wappointment&sfp_email=&sfph_mail=
https://www.wordfence.com/threat-intel/vulnerabilities/id/07069f39-f892-4c19-8e0b-e5e17b1ffb21?source=cve
cvelogic Threat Intelligence