CVE-2026-56707 in Flex Objects Plugin
Summary
by MITRE • 08/25/2026
Grav Flex Objects plugin versions 1.4.0 through 1.4.7 contain an authorization bypass vulnerability in the flex-objects shortcode that allows users with page-edit access to render any registered Flex collection without permission checks. Attackers can place the shortcode in published pages to expose sensitive directory contents including user account information, bypassing the authorize ACL enforced in the admin panel.
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Analysis
by VulDB Data Team • 08/25/2026
The Grav CMS platform relies on a modular architecture where plugins extend core functionality, and among these is the Flex Objects plugin which manages structured data collections such as users, forms, or custom entities. Versions 1.4.0 through 1.4.7 of this plugin contain a critical authorization bypass vulnerability within its shortcode implementation. This flaw stems from an insufficient access control mechanism that fails to validate user permissions before rendering registered Flex collections via the flex-objects shortcode. The technical root cause lies in the shortcodes processing logic which does not properly enforce the Access Control List (ACL) rules defined for specific object types or actions, allowing any authenticated user with page-edit privileges to invoke these shortcodes regardless of their actual rights regarding the underlying data objects.
This vulnerability enables attackers who have been granted basic editing permissions on pages within a Grav installation to bypass administrative security controls and expose sensitive information stored in Flex collections. By embedding the vulnerable shortcode into published content, an attacker can trigger the rendering of any registered collection without undergoing proper authorization checks. This effectively circumvents the ACL enforcement that is typically applied through the admin panel interface, leading to unauthorized data exposure. The operational impact includes the potential leakage of user account details such as usernames and hashed passwords if stored in accessible collections, along with other sensitive configuration or business-critical data depending on how the site administrator has configured their Flex objects.
From a classification perspective, this issue aligns with CWE-269 Improper Privilege Management where an actor is able to escalate privileges or access resources beyond their assigned role due to flawed logic in permission checks. In terms of attack vectors and tactics, it corresponds to ATT&CK technique T1078 Valid Accounts as the exploitation requires valid credentials with at least page-edit rights, and potentially relates to data exfiltration techniques if sensitive information is successfully retrieved through this method. The vulnerability highlights a common risk in web applications where frontend-facing features like shortcodes are not subjected to the same rigorous security validation as backend administrative endpoints.
To mitigate this vulnerability, administrators must immediately upgrade the Grav Flex Objects plugin to version 1.4.8 or later which addresses these authorization checks and ensures that all shortcode invocations respect existing ACL policies. Until an update is applied, site owners should restrict page-edit permissions to trusted users only and monitor for unusual content modifications involving flex-objects shortcodes. Additionally implementing strict input validation on the server side before processing any dynamic data rendering requests can provide a layer of defense against similar logic flaws in other plugins or custom code within the Grav ecosystem.