The Gallery Block (Meow Gallery) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘data_atts’ parameter in versions up to, and including, 5.1.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Meow Gallery WordPress plugin before 4.1.9 does not sanitise, validate or escape the ids attribute of its gallery shortcode (available for users as low as Contributor) before using it in an SQL statement, leading to an authenticated SQL Injection issue. The injection also allows the returned values to be manipulated in a way that could lead to data disclosure and arbitrary objects to be deserialized.