CVE-2026-8867

The Post Category Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin’s ‘postcategorygallery’ shortcode in versions up to, and including, 1.0.0. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes (such as total_width, color_scheme, and caption_font_size) inside the sc_horcatbar() function, which are concatenated directly into HTML attribute values. 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.

More information : https://plugins.trac.wordpress.org/browser/post-category-gallery/trunk/horcatbar.php#L79