CVE-2026-104000 HIGH

CVE-2026-104000: Simply Schedule Appointments <= 1.6.12.35 - Unauthenticated Stored Cross-Site Scripting via 'status' Parameter via /wp-json/ssa/v1/appointments/{id}

Vendor Croixhaug
Product Simply Schedule Appointments
Weakness CWE-79 · XSS
Published October 16, 2026
Last update October 16, 2026
View on NVD All CVEs

CVSS base score

7.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

October 16, 2026 CVE published
October 16, 2026 Record updated

Related vulnerabilities

04Related CVE

CVE-2026-81778 WordPress Kalles Addons plugin <= 1.0.6 - Cross Site Scripting (XSS) vulnerability CVE-2026-4246 ElementsKit Pro <= 4.10.1 - Unauthenticated Stored Cross-Site Scripting via 's' Parameter CVE-2026-78289 WordPress CozyStay theme <= 1.10.0 - Cross Site Scripting (XSS) vulnerability CVE-2026-28166 WordPress Tourmaster plugin <= 5.4.9 - Cross Site Scripting (XSS) vulnerability CVE-2026-18328 Forminator Forms <= 1.57.0 - Unauthenticated DOM-Based Cross-Site Scripting via 'error_description' Parameter