CVE-2026-4300

The Robo Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Loading Label' setting in all versions up to, and including, 5.1.3. The plugin uses a custom |*...*| marker pattern in its fixJsFunction() method to embed raw JavaScript function references within JSON-encoded configuration objects. When a gallery's options are rendered on the frontend, json_encode() wraps all string values in double quotes. The fixJsFunction() method then strips the "|* and *|" sequences, effectively converting a JSON string value into raw JavaScript code. The Loading Label field (stored as rbs_gallery_LoadingWord post_meta) is an rbstext type field that is sanitized with sanitize_text_field() on save. While this strips HTML tags, it does not strip the |*...*| markers since they contain no HTML. When a user inputs |*alert(document.domain)*|, the value passes through sanitization intact, is stored in post_meta, and is later retrieved and output within an inline ` tag via renderMainBlock() with the quote markers stripped — resulting in arbitrary JavaScript execution. The gallery post type uses capability_type => 'post'`, allowing Author-level users to create galleries. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses a page containing the gallery shortcode.