The Cozy Blocks – Page Builder for Gutenberg Editor & FSE with 700+ Patterns, 58 Blocks & Templates plugin for WordPress is vulnerable to Stored Cross-Site Scripting via cozyHoverEffect Block Attribute in all versions up to, and including, 2.2.16 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. The payload survives wp_kses_post on save because it contains no angle brackets — only a double-quote breakout of the cozyHoverEffect.boxShadow.color attribute value — allowing event-handler injection at the render stage.