CVE-2026-104000

high

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.

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/3a8bd422-112c-43bc-a041-3c6eea27b790?source=cve

https://plugins.trac.wordpress.org/changeset/3746344/simply-schedule-appointments/trunk/includes/class-appointment-model.php

https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.33/includes/class-utils.php#L716

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-appointment-model.php#L1490

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-102663

Details

Source: Mitre, NVD

Published: 2026-10-16

Updated: 2026-10-16

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 7.2

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Severity: High

EPSS

EPSS: 0.00236