CVE-2026-77116 in Brave Popup Builder Plugin
Summary
by MITRE • 08/23/2026
Brave Popup Builder (slug: brave-popup-builder) has a broken access control issue in versions through 0.8.5. Any logged-in user - Subscriber or WooCommerce Customer is enough — can read popup content they shouldn't have access to by passing a post ID in the URL.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 08/23/2026
The vulnerability identified in Brave Popup Builder, specifically affecting versions up to and including 0.8.5, represents a critical failure in server-side authorization logic known as broken object level permissions. This flaw allows authenticated users with minimal privileges, such as subscribers or standard WooCommerce customers, to bypass intended access restrictions by directly manipulating the post identifier passed via URL parameters. In typical web application architecture, content visibility is governed not only by user authentication but also by strict role-based access controls that verify whether a specific user has permission to view, edit, or delete a particular resource instance. The vulnerability arises because the plugin fails to validate these permissions against the requested popup ID before rendering the associated data. Consequently, an attacker can enumerate valid post IDs and retrieve sensitive content intended for other users or restricted audiences simply by altering the numerical identifier in the request URL.
From a technical perspective, this issue stems from insufficient input validation regarding object ownership and access rights. When a user requests a resource identified by a specific ID, the application must cross-reference that ID with the current session's permissions to ensure the action is authorized. In this case, the backend logic likely retrieves the popup content based solely on the provided identifier without checking if the requesting user has the requisite role or ownership status. This oversight aligns directly with CWE-639, which describes authorization bypass through direct object reference manipulation. The absence of proper checks means that any authenticated account can act as a privileged actor for specific resources, effectively elevating their capabilities beyond what was granted by their assigned role.
The operational impact of this vulnerability is significant, particularly in environments where popup content contains sensitive information such as personalized marketing data, exclusive offers, or internal communications intended only for administrators or premium members. An attacker can systematically iterate through post IDs to harvest a substantial amount of unauthorized data. This capability facilitates both passive reconnaissance and active data exfiltration depending on the volume of accessible popups. Furthermore, because the exploit requires no complex payload construction beyond URL modification, it is easily executable using automated tools or simple browser manipulation, lowering the barrier for entry significantly. The attack vector falls under MITRE ATT&CK technique T1078, which covers valid accounts and specifically relates to unauthorized access through legitimate credentials due to poor privilege management.
To mitigate this vulnerability, immediate action should be taken by upgrading Brave Popup Builder to a version where this authorization check has been implemented correctly. Developers must ensure that every request for popup content includes rigorous server-side validation of the user's role against the specific resource being accessed. Implementing consistent access control checks at the data layer rather than relying solely on frontend restrictions is essential to prevent such bypasses. Until an update is available, administrators should consider restricting public access to certain endpoints if possible or monitoring logs for unusual patterns of post ID enumeration by low-privilege users. Regular security audits and adherence to secure coding standards that emphasize principle of least privilege will help prevent similar authorization flaws in future iterations of the software.