CVE-2026-5920: Bold Page Builder <= 5.9.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'shortcode_content' Parameter
The Bold Page Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'shortcodecontent' parameter of the btbbshortcode shortcode in all versions up to, and including, 5.9.6. This is due to a bypassable security filter (btbbsavepre) that can be circumvented via null byte injection, combined with insufficient output sanitization of base64-decoded content in the btbbrawcontent shortcode handler. 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.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this vulnerability?
An attacker needs an authenticated WordPress account with Contributor-level permissions or higher. They can inject malicious script content into a page through the affected shortcode parameter.
What has to happen for the injected script to run?
The script executes when a user accesses a page containing the attacker-injected content. This creates exposure for users who view affected pages, including higher-privileged site users.
Are default installations affected?
The issue affects Bold Page Builder versions through 5.9.6 when the vulnerable shortcode functionality is available. Exploitation also requires an attacker to have at least Contributor access; it is not described as exploitable by an unauthenticated visitor.
How can I check for possible exploitation?
Review pages created or edited by Contributor-level and higher accounts for use of the bt_bb_shortcode shortcode, especially shortcode_content values containing unexpected encoded content or null-byte injection attempts. Also inspect rendered pages for unexpected script execution or injected content.