CVE-2026-16645 in PhotoSwipe Plugin
Summary
by MITRE • 08/26/2026
Missing Authorization vulnerability in Drupal PhotoSwipe - Responsive JavaScript Modal Image Gallery allows Forceful Browsing. This issue affects PhotoSwipe - Responsive JavaScript Modal Image Gallery versions: from 0.0.0 to 3.2.0.
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Analysis
by VulDB Data Team • 08/26/2026
The identified security flaw resides within the Drupal module known as PhotoSwipe, specifically in its responsive JavaScript modal image gallery functionality. This vulnerability is classified under CWE-862, which denotes a Missing Authorization issue, and it fundamentally represents an instance of Forceful Browsing where an attacker can access resources without proper permission checks. The affected versions span from 0.0.0 up to and including version 3.2.0, indicating that this security gap has persisted across multiple releases since the module's inception or significant refactoring phases. In a typical web application architecture, authorization mechanisms are designed to ensure that only authenticated users with specific roles can access certain endpoints or execute particular actions. However, in this case, the underlying code fails to validate whether the requesting user possesses the necessary privileges before processing requests related to image gallery operations.
From a technical perspective, the vulnerability likely stems from an absence of robust server-side validation for administrative functions or sensitive data retrieval within the module's API endpoints or AJAX handlers. When a user interacts with the PhotoSwipe interface, particularly when attempting to view, edit, or manage images in a modal context, the application may rely solely on client-side JavaScript checks rather than enforcing strict access controls at the backend level. This architectural oversight allows an unauthenticated attacker or a low-privilege authenticated user to bypass intended restrictions by directly invoking these endpoints with crafted HTTP requests. By manipulating parameters such as node IDs or image identifiers in the request payload, the adversary can force the server to execute operations that should be restricted to administrators or authorized content editors. This behavior aligns closely with MITRE ATT&CK technique T1078, Valid Accounts, if exploitation requires any level of authentication, or more broadly with unauthorized access patterns where privilege escalation is achieved through improper enforcement of security policies rather than exploiting a software bug in the logic itself.
The operational impact of this vulnerability is significant for Drupal site administrators and content managers who rely on secure media management workflows. An attacker leveraging this flaw can potentially view private images that are not publicly accessible, extract metadata from sensitive documents or photos stored within the gallery, or even modify image configurations if write permissions are also improperly enforced alongside read access. In scenarios where the module is used for internal corporate communications or customer-facing galleries with restricted content, this exposure could lead to data leakage and compliance violations under regulations such as GDPR or HIPAA depending on the nature of the exposed media. Furthermore, because PhotoSwipe is a widely adopted module, successful exploitation can serve as an initial foothold for more complex attacks, including cross-site scripting if user input is not sanitized in subsequent processing steps, although the primary vector here remains unauthorized access to resources.
To mitigate this risk, immediate action must be taken by upgrading the Drupal PhotoSwipe module to version 3.2.1 or any later release where the authorization checks have been properly implemented and tested. Site administrators should verify that all instances of the vulnerable code path now include rigorous server-side validation ensuring that only users with explicit permissions can access specific gallery endpoints. Additionally, implementing a Web Application Firewall rule set designed to detect anomalous patterns in AJAX requests targeting media management APIs can provide an additional layer of defense during the transition period. Regular security audits and penetration testing focused on authorization bypasses are recommended to ensure that no other modules or custom code within the Drupal installation suffer from similar deficiencies. Maintaining up-to-date dependencies is critical, as open-source projects frequently patch such logical flaws in subsequent minor releases to preserve the integrity and confidentiality of hosted content.