CVE-2026-76801

Deferred Deferred - Pending Action

Remote Code Execution in FireBox WooCommerce Popup Builder WordPress Plugin

Publication date: 2026-09-09

Last updated on: 2026-09-09

Assigner: Wordfence

Description

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 wp_insert_user, update_option, and file_put_contents, combined with no sanitization of PHP condition rule values stored via the firebox_meta 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 edit_fireboxes and publish_fireboxes capabilities to the Author role, lowering the effective entry point to Author-level access.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-09

Last Modified

2026-09-09

Generated

2026-09-29

AI Q&A

2026-09-10

EPSS Evaluated

2026-09-27

NVD

CVE-2026-76801

EUVD

EUVD-2026-74567

Affected Vendors & Products

Vendor	Product	Version / Range
firebox	woocommerce_popup_builder	to 3.1.10 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-269	The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

Attack-Flow Graph

Executive Summary

This vulnerability allows authenticated attackers with author-level access or higher to execute remote code on the server. It exists in the FireBox WooCommerce Popup Builder plugin for WordPress up to version 3.1.10. The issue stems from a weak regex blacklist that fails to block dangerous WordPress functions like wp_insert_user and file_put_contents. Attackers can exploit this by sending malicious values via the firebox_meta REST endpoint.

Detection Guidance

Check WordPress sites using the FireBox – WooCommerce Popup Builder plugin for versions up to 3.1.10. Inspect server logs for unauthorized use of functions like wp_insert_user, update_option, or file_put_contents. Look for suspicious REST API calls to firebox_meta endpoints with PHP condition rule values.

Impact Analysis

If you use the affected plugin, an attacker could take full control of your WordPress site. They might steal data, install malware, deface your site, or use it to attack other systems. The vulnerability requires only author-level access, which is relatively low privilege, making it easier for attackers to exploit.

Compliance Impact

This vulnerability could lead to data breaches, which would violate GDPR and HIPAA requirements for data protection. If attackers gain access, they may exfiltrate sensitive user data, leading to legal penalties, fines, and reputational damage for organizations handling personal or health information.

Mitigation Strategies

Update the FireBox plugin to the latest version beyond 3.1.10 immediately. Remove or restrict Author role capabilities edit_fireboxes and publish_fireboxes. Monitor for unauthorized file changes or code execution attempts. Consider temporary removal of the plugin if an update is unavailable.

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