The 3D FlipBook – PDF Embedder, PDF Flipbook Viewer, Flipbook Image Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘style’ and 'mode' parameters in all versions up to, and including, 1.16.15 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. Note: This issue affects only block-based themes.