The Appointment Booking Calendar plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 1.3.96. This is due to the plugin exposing an unauthenticated booking processing endpoint (cpabc_appointments_check_IPN_verification) that trusts attacker-supplied payment notifications without verifying their origin, authenticity, or requiring proper authorization checks. This makes it possible for unauthenticated attackers to arbitrarily confirm bookings and insert them into the live calendar via the 'cpabc_ipncheck' parameter, triggering administrative and customer notification emails and disrupting operations.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 5.3NVD modified 2026-10-18 20:10
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 5
- https://plugins.trac.wordpress.org/browser/appointment-booking-calendar/tags/1.3.96/inc/cpabc_apps_go.inc.php#L14
- https://plugins.trac.wordpress.org/browser/appointment-booking-calendar/tags/1.3.96/inc/cpabc_apps_go.inc.php#L363
- https://plugins.trac.wordpress.org/browser/appointment-booking-calendar/tags/1.3.96/inc/cpabc_apps_go.inc.php#L476
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3399113%40appointment-booking-calendar&new=3399113%40appointment-booking-calendar&sfp_email=&sfph_mail=
- https://www.wordfence.com/threat-intel/vulnerabilities/id/638217c4-7a37-49e4-8660-5510ace692ec?source=cve