CVE-2026-76801: FireBox <= 3.1.10 - Authenticated (Author+) Remote Code Execution to Privilege Escalation
The FireBox – WooCommerce Popup Builder, Exit Intent Popup, Email Optin & Cart Abandonment plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 3.1.10 via the value function. This is due to a trivially bypassable regex blacklist in Executer::allowedToRun() that fails to block WordPress core functions such as wpinsertuser, updateoption, and fileputcontents, combined with no sanitization of PHP condition rule values stored via the fireboxmeta REST endpoint. This makes it possible for authenticated attackers, with author-level access and above, to execute code on the server. On sites upgraded from a version prior to 3.1.10, the Migrator::preserveCampaignRoleAccess() function automatically grants the editfireboxes and publishfireboxes capabilities to the Author role, lowering the effective entry point to Author-level access.
Affected Software
Event History
Frequently Asked Questions
Which users can realistically exploit this issue?
An authenticated user with Author-level access or higher can exploit it. On sites upgraded from a version before 3.1.10, migration automatically grants Authors the edit_fireboxes and publish_fireboxes capabilities, making Author accounts an effective entry point.
What access and interaction does exploitation require?
The attacker must be authenticated and able to act with the relevant FireBox capabilities. No user interaction is required, and the vulnerable condition-rule values are stored through the firebox_meta REST endpoint.
What can an attacker do after exploiting the flaw?
The flaw allows server-side code execution. The described bypass can invoke WordPress functions including wp_insert_user, update_option, and file_put_contents, which can support privilege escalation and high-impact changes to the site.
How can I determine whether Authors may have the required FireBox permissions?
Review whether the site was upgraded from a FireBox version earlier than 3.1.10 and inspect the Author role for the edit_fireboxes and publish_fireboxes capabilities. The migration routine described automatically preserves these capabilities for Authors on such upgraded sites.