The Tournamatch WordPress plugin before 4.6.1 does not sanitise and escape some parameters, which could allow users with a role as low as subscriber to perform Cross-Site Scripting attacks.

The Tournamatch WordPress plugin before 4.6.1 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)

The Tournamatch plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'trn-ladder-registration-button' shortcode in all versions up to, and including, 4.6.1 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.