# Simply Schedule Appointments <= 1.6.12.35 - Unauthenticated Stored Cross-Site Scripting via Debug Log

- **ID:** WPSEC-2026-1014
- **Plugin:** Simply Schedule Appointments (`simply-schedule-appointments`), https://wordpress.org/plugins/simply-schedule-appointments/
- **Affected versions:** from 1.6.11.9 before 1.6.12.37
- **Fixed in:** 1.6.12.37 (Update to 1.6.12.37 or later.)
- **Severity:** High 7.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Medium, affected versions Medium (as of 2026-10-15)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/simply-schedule-appointments
- **Fix released:** 2026-10-14
- **Published:** 2026-10-15
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1014/

## Description

The Simply Schedule Appointments plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the debug log in versions 1.6.11.9 up to, and including, 1.6.12.35, due to values submitted when an appointment is changed being written to the log, and the log viewer printing the log without output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator views the debug log.

## References

- https://wpsec.com/vuln/WPSEC-2026-1014/
- https://plugins.svn.wordpress.org/simply-schedule-appointments/tags/1.6.12.37/
- https://wordpress.org/plugins/simply-schedule-appointments/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1014/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.