CVE-2026-107251 in Entity Reference Manager
Summary
by MITRE • 10/30/2026
Incorrect Authorization vulnerability in Drupal Entity Reference Manager (Merge entities) allows Forceful Browsing. This issue affects Entity Reference Manager (Merge entities) versions: from 0.0.0 to 1.0.3.
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Analysis
by VulDB Data Team • 10/30/2026
The identified security flaw resides within the Entity Reference Manager module for Drupal, specifically affecting the functionality designed to merge user or content entities across versions ranging from initial release up through version 1.0.3. This vulnerability is classified as an incorrect authorization issue that facilitates forceful browsing, a category of attacks where an attacker exploits insufficient access controls to interact with resources they are not authorized to view or modify. In the context of Drupal's architecture, entity management operations often require specific permissions and role-based checks to ensure data integrity and user privacy. The failure in these checks allows authenticated users who lack the necessary administrative privileges to execute merge operations on entities that belong to other users or restricted content types.
From a technical perspective, the root cause lies in the absence of robust authorization logic within the merge endpoint or handler. When an administrator initiates a merge operation, the system is designed to consolidate data from one entity into another while preserving referential integrity and updating associated fields. However, due to the flawed implementation, the application does not adequately verify whether the requesting user has permission to perform this action on the specific target entities involved in the merge process. This oversight effectively bypasses Drupal's standard role-based access control mechanisms, allowing a lower-privileged user to manipulate high-value data structures. The vulnerability aligns with CWE-284, which describes Improper Access Control, and can be mapped to MITRE ATT&CK technique T1078, Valid Accounts, as it involves the misuse of legitimate credentials to perform unauthorized administrative functions.
The operational impact of this vulnerability is significant for any Drupal site relying on the Entity Reference Manager module for complex data relationships or user management workflows. An attacker with a standard authenticated account could potentially merge sensitive entities, leading to data corruption, loss of audit trails, and exposure of private information that should remain segregated between different users or content categories. For instance, merging two user profiles might inadvertently expose personal details from one profile into another accessible by the merged entity's new owner or other authorized viewers. Furthermore, such unauthorized merges can disrupt business logic dependent on distinct entity boundaries, potentially causing application errors or inconsistent data states that are difficult to trace back to their origin without proper logging and monitoring in place.
Mitigation strategies must prioritize immediate remediation through software updates as well as defensive configuration measures if updating is not immediately feasible. The primary recommendation is to upgrade the Entity Reference Manager module to version 1.0.4 or later, where this authorization check has been corrected by the maintainers. In environments where patching cannot occur instantly, administrators should restrict access to the affected merge endpoints using web application firewall rules that block requests containing specific parameters associated with the merge operation from non-administrative IP addresses or user agents. Additionally, implementing strict logging and monitoring for entity modification events can help detect anomalous behavior indicative of exploitation attempts. Regular audits of role permissions within Drupal ensure that only trusted users possess the capabilities to perform high-impact administrative actions, thereby reducing the attack surface available to potential adversaries seeking to exploit authorization flaws.