The Page Builder by SiteOrigin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via panels_data Parameter in all versions up to, and including, 2.34.3 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. This is possible because the nonce and edit_post capability checks enforced during save are both satisfied by Contributor-level users for their own posts, and the panels_data value is stored as post meta — outside the scope of WordPress's unfiltered_html carve-out — meaning no wp_kses fallback prevents the unsanitized WP_Widget_Custom_HTML content from being persisted and later rendered verbatim on the frontend.

Quoted source text, attributed separately from HOL analysis.

The Page Builder by SiteOrigin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via panels_data Parameter in all versions up to, and including, 2.34.3 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. This is possible because the nonce and edit_post capability checks enforced during save are both satisfied by Contributor-level users for their own posts, and the panels_data value is stored as post meta — outside the scope of WordPress's unfiltered_html carve-out — meaning no wp_kses fallback prevents the unsanitized WP_Widget_Custom_HTML content from being persisted and later rendered verbatim on the frontend.

Quoted source text, attributed separately from HOL analysis.