Vulnerability in Simply Schedule Appointments — CVE-2026-104000

What to do now

Update Simply Schedule Appointments to 1.6.12.37 or later.

Affected versions

• Everything up to and including 1.6.12.35

The Simply Schedule Appointments plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'status' parameter in all versions up to, and including, 1.6.12.35 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The malicious payload is stored unconditionally because debug logging is enabled by default, and the debug-log viewer is accessible to anyone holding the site-wide Support PIN (an HMAC-MD5 of AUTH_SALT displayed in wp-admin), meaning the injected script will execute against the administrator's session during ordinary support or troubleshooting workflows.

This description is reproduced verbatim from the public vulnerability record.

• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.33/includes/class-appointment-model.php#L1490
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.33/includes/class-debug.php#L92
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.33/includes/class-utils.php#L716
• https://plugins.trac.wordpress.org/changeset/3746344/simply-schedule-appointments/trunk/includes/class-appointment-model.php
• https://www.wordfence.com/threat-intel/vulnerabilities/id/3a8bd422-112c-43bc-a041-3c6eea27b790?source=cve

This page is compiled automatically from public databases. Accuracy is not guaranteed; confirm against the vendor advisory before acting.