CVE-2025-9851: Gentlesource Appointmind

Medium severity, CVSS 6.4. EPSS: 0.2% chance of exploitation in the next 30 days.

The Appointmind plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'appointmind_calendar' shortcode in all versions up to, and including, 4.1.0 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Affected products

• Gentlesource Appointmind: up to and including 4.1.0

Published 2025-09-17. Last modified 2026-06-17.