The B Slider- Gutenberg Slider Block for WP plugin for WordPress is vulnerable to Information Exposure in all versions up to, and including, 1.9.5 via the 'bsb-slider' shortcode due to insufficient restrictions on which posts can be included. This makes it possible for authenticated attackers, with Contributor-level access and above, to extract data from private posts that they should not have access to.
https://plugins.trac.wordpress.org/changeset/3228644/b-slider/trunk/custom-post.php