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.

SeverityHigh
CVSS7.2
Exploit probability—
ProductSimply Schedule Appointments
PublishedOct 16, 2026
First seenOct 16, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
croixhaug Simply Schedule Appointmentsv ≤ 1.6.12.35—

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CVE-2026-104000 · Simply Schedule Appointments · Dark Radar