CVE-2026-87954 in Taxonomy Term Glossary Plugin
Summary
by MITRE • 10/22/2026
Missing Authorization vulnerability in Drupal Taxonomy Term Glossary allows Forceful Browsing. This issue affects Taxonomy Term Glossary versions: from 0.0.0 to 4.6.0.
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Analysis
by VulDB Data Team • 10/22/2026
The identified security flaw resides within the Drupal module known as Taxonomy Term Glossary, specifically affecting version ranges from 0.0.0 through 4.6.0. This vulnerability is classified under Common Weakness Enumeration (CWE) ID CWE-285, which denotes Improper Authorization, and aligns with MITRE ATT&CK technique T1078, Valid Accounts or Default Accounts if default credentials are leveraged for access. The core issue stems from a failure in the application logic to enforce adequate access controls on specific endpoints exposed by the module. In a properly secured web application, every request intended to modify state or retrieve sensitive data must be validated against the current user's permissions and session context. However, in this instance, the Taxonomy Term Glossary module fails to verify whether the requesting entity possesses the necessary privileges before processing requests directed at protected resources.
This architectural oversight results in a Forceful Browsing scenario where an unauthenticated or unauthorized attacker can directly access administrative functions or sensitive data structures that are intended for privileged users only. By manipulating URLs or sending crafted HTTP requests, an adversary can bypass standard authentication mechanisms and interact with the module's internal features as if they were an administrator. This lack of server-side validation allows attackers to exploit the application logic rather than relying on client-side restrictions which can be easily circumvented using common web proxies or scripting tools. The vulnerability essentially treats all incoming requests equally regardless of the user identity associated with them, creating a significant gap in the defense-in-depth strategy employed by many Drupal deployments.
The operational impact of this vulnerability is severe due to the nature of the Taxonomy Term Glossary module and its integration within the broader Drupal ecosystem. If an attacker successfully exploits this missing authorization check, they may gain unauthorized access to taxonomy management features, potentially allowing them to alter term definitions, inject malicious content into glossaries, or disrupt site functionality by deleting critical data structures. In environments where this module is used for knowledge bases or documentation systems, such tampering can lead to misinformation and reputational damage. Furthermore, depending on the specific implementation details of how these endpoints interact with other modules, there may be secondary risks involving Cross-Site Scripting (XSS) if user input within glossary terms is not properly sanitized before rendering, although the primary vector here remains unauthorized access via forceful browsing.
To mitigate this risk, immediate action must be taken by site administrators to update the Taxonomy Term Glossary module to a version later than 4.6.0 where these authorization checks have been corrected. Until an upgrade is feasible, temporary mitigations should include restricting direct access to affected endpoints through web server configuration rules if possible, although this is often difficult without breaking legitimate functionality. It is also critical to audit user roles and permissions within the Drupal administration interface to ensure that only trusted individuals are assigned high-level privileges. Regular security audits and penetration testing focused on broken object level authorization (BOLA) patterns can help identify similar vulnerabilities in other custom or contributed modules, ensuring a more robust posture against unauthorized access attempts across the entire application surface area.