CVE-2026-13358

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

MEDIUM

6.5

CVSS Score

Published: August 16, 2026 at 04:24 AM UTC

Updated: August 20, 2026 at 01:05 PM UTC

1 product affected across 1 vendorSimply Schedule Appointments

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Severity

MEDIUM6.5

Exploit prediction

EPSS 0.7%

SSVC

No known exploit

Description

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.