CVE-2026-13358mediumCWE-639

CVE-2026-13358: medium-severity vulnerability in croixhaug Simply Schedule Appointments

Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.12.10 - Authenticated (Contributor+) Insecure Direct Object Reference to Sensitive Information Exposure

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13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 6.5epss 0.7%
The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.6.12.10 via the ssa_past_appointments due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with contributor-level access and above, to access appointment records belonging to arbitrary users and harvest the per-appointment ownership tokens (32-character hashes) embedded in the rendered HTML, which can then be used without any authentication to read or modify those appointments including full customer PII such as name, email, phone number, and private notes. The /wp-json/ssa/v1/render-shortcode REST endpoint is registered unconditionally on rest_api_init regardless of whether the Divi theme is installed, and its permission callback only requires current_user_can('edit_posts'), meaning any Contributor-level account is sufficient to trigger this entire exploit chain.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Affected products
croixhaug · Simply Schedule Appointments
Related CVEs — croixhaug Simply Schedule Appointments

In the same product, most dangerous first.

CVE-2026-89294HIGHSimply Schedule Appointments <= 1.6.12.27 - Authenticated (Subscriber+) Local File Inclusion via 'ssa_locale' ParameterEPSS 1.0%CVE-2026-92245HIGHSimply Schedule Appointments <= 1.6.12.32 - Missing Authorization to Unauthenticated Sensitive Information Exposure and Arbitrary Appointment Deletion via 'recursive' Parameter on the appointment_types REST Endpoint via Public NonceEPSS 0.4%CVE-2026-91109MEDIUMSimply Schedule Appointments <= 1.6.12.31 - Insecure Direct Object Reference to Authenticated (Subscriber+) Sensitive Information Disclosure via 'complete_group' ParameterEPSS 0.3%CVE-2026-104000HIGHSimply Schedule Appointments <= 1.6.12.35 - Unauthenticated Stored Cross-Site Scripting via 'status' Parameter via /wp-json/ssa/v1/appointments/{id}EPSS 0.2%CVE-2026-6723MEDIUMAppointment Booking Calendar <= 1.6.11.11 - Incorrect Authorization to Unauthenticated Sensitive Field Modification via Appointment Public TokenEPSS 0.2%