[ CVE-2026-104000 · Published 16 Oct 2026 ]
Vulnerability in croixhaug Simply Schedule Appointments
[ Description ]Official description
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.
[ Fixes ]Fixes and patches
No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.
[ References ]References
- plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.33/includes…
- plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.33/includes…
- plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.33/includes…
- plugins.trac.wordpress.org/changeset/3746344/simply-schedule-appointments/trunk/include…
- www.wordfence.com/threat-intel/vulnerabilities/id/3a8bd422-112c-43bc-a041-3c6eea27b790