CVE-2026-62670 in Flex Objects Plugin
Summary
by MITRE • 08/19/2026
Grav Flex Objects Plugin allows you to build custom collections of objects. Prior to 1.4.3, the Grav Flex Objects Admin Next API requireFlexPermission() method in classes/Api/FlexApiController.php returns without denying access when a directory blueprint omits config.admin.permissions. An authenticated account with only api.access can use the index, show, create, update, delete, export, and media handlers for a permission-less directory even though the core admin.flex-object. authorization fallback would deny the same actions. This issue is fixed in version 1.4.3.
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Analysis
by VulDB Data Team • 08/19/2026
The Grav Flex Objects plugin serves as a critical component for developers seeking to construct custom collections of objects within the Grav content management system architecture. By leveraging this extension, administrators and developers can define structured data models that extend beyond standard page-based content, enabling complex application logic directly within the CMS environment. The security integrity of these extensions relies heavily on consistent enforcement of access control policies across all interaction points, particularly when exposed through administrative interfaces or API endpoints. In versions prior to 1.4.3, a significant discrepancy existed in how authorization checks were performed between different layers of the system's request handling pipeline.
The core vulnerability stems from an inconsistency in permission validation logic within the Flex Objects Admin Next API implementation. Specifically, the requireFlexPermission method located in classes/Api/FlexApiController.php fails to properly enforce access restrictions when a directory blueprint does not explicitly define config.admin.permissions. In such scenarios where configuration data is incomplete or omitted for specific directories, this method returns without denying unauthorized requests. This behavior creates an unintended bypass mechanism that allows authenticated users with only basic api.access privileges to perform sensitive operations including index listing, show retrieval, creation of new objects, updates, deletion, exportation, and media handling against these permission-less directories.
This flaw represents a classic case of inconsistent authorization enforcement where the API layer operates under different security assumptions than the core administrative interface. The Grav core admin.flex-object authorization mechanism correctly denies access to users lacking sufficient privileges for similar actions when interacting through standard administrative pathways. However, because the Flex Objects Admin Next API does not inherit or replicate this strict fallback behavior, it effectively creates a parallel execution path with weaker security controls. An attacker possessing valid credentials and minimal api.access rights can exploit this gap to manipulate data structures that should otherwise be restricted, potentially leading to unauthorized data modification, information disclosure through listing operations, or complete removal of critical content objects.
From a classification perspective, this vulnerability aligns closely with CWE-284 Improper Access Control, specifically illustrating how inconsistent implementation of security policies across different components can undermine overall system integrity. The exploitation technique involves leveraging valid authentication credentials to access resources that should be restricted based on role-based permissions, which corresponds to ATT&CK tactic T1078 Valid Accounts and the specific sub-technique of abusing misconfigured roles or privileges within an application layer. This type of flaw is particularly dangerous because it does not require external exploitation vectors such as injection attacks but rather relies solely on logical errors in permission checking routines accessible by any authenticated user with limited scope.
The operational impact of this vulnerability allows for the compromise of data integrity and confidentiality within Grav installations utilizing Flex Objects. Attackers can enumerate sensitive object collections, extract private information through show handlers, inject malicious content via create or update operations, and destroy important records using delete functions. Since media handling is also affected, there may be implications regarding unauthorized file uploads or access to stored assets depending on how the underlying storage mechanisms are configured. The existence of this bypass means that security policies defined at a higher level in the CMS core cannot guarantee protection for resources managed through the Flex Objects API if their blueprints lack explicit permission definitions.
Mitigation strategies primarily involve upgrading the Grav Flex Objects plugin to version 1.4.3 or later, where the requireFlexPermission method has been corrected to ensure consistent denial of access when permissions are not explicitly defined in directory blueprints. Administrators should also review existing blueprint configurations and consider implementing default deny policies by ensuring all custom object directories include explicit config.admin.permissions settings that restrict access to authorized roles only. Regular auditing of API endpoint behaviors against core administrative controls is recommended to detect similar inconsistencies in other plugins or extensions, thereby maintaining a robust defense-in-depth posture within the content management ecosystem.