Medium · published September 18, 2026
The VK All in One Expansion Unit plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'vkExUnit_cta_img_position' Post Meta in all versions up to, and including, 9.118.0 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 sanitize_text_field callback applied on save does not strip double-quote characters or on* event-handler attributes, and the output filter Vk_Call_To_Action::safe_kses_post() only rewrites disallowed iframe elements while returning all other content verbatim, leaving the injected payload intact in the rendered HTML.