Osom Blocks <= 1.2.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via class_name Parameter

The Osom Blocks – Custom Post Type listing block plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘class_name’ parameter in all versions up to, and including, 1.2.1 due to insufficient input sanitization and output escaping. 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.