CVE-2026-77026 in Convert Forms Extension
Summary
by MITRE • 08/20/2026
Joomla Extension - tassos.gr - Client-controlled validation bypass in Convert Forms extension < 5.2.5 - The front-end Submissions view did not enforce access control. An unauthenticated visitor could therefore list a form's submissions.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in the Convert Forms extension for Joomla, specifically versions prior to 5.2.5, represents a critical failure in server-side access control mechanisms within the application's front-end architecture. This flaw stems from an improper validation of user permissions when handling requests directed at the Submissions view component. In secure web applications, any operation that involves accessing sensitive data such as form submissions must be preceded by rigorous authentication and authorization checks to ensure that only authorized users with appropriate privileges can retrieve or manipulate this information. However, in this specific implementation, the backend logic responsible for rendering the list of form submissions failed to verify whether the requesting user possessed the necessary administrative rights or valid session tokens before processing the request. This oversight allows any entity interacting with the application via standard HTTP requests to bypass these security controls entirely.
From a technical perspective, this vulnerability is classified under CWE-284, which describes Improper Access Control, and aligns with MITRE ATT&CK technique T1078, Valid Accounts, as it involves exploiting misconfigured permissions to gain unauthorized access. The core issue lies in the lack of server-side enforcement for view-level security. While Joomla itself provides a robust framework for managing user groups and permissions, extensions developed by third parties must explicitly integrate these checks into their custom components. In this case, the developer neglected to implement or correctly invoke the necessary ACL (Access Control List) methods before outputting data related to form submissions. Consequently, an unauthenticated visitor can construct specific URLs pointing to the submission listing endpoint without needing to log in or provide any credentials. The server processes these requests as if they were coming from a privileged user, thereby exposing internal operational data that was intended to be restricted.
The operational impact of this vulnerability is significant due to the nature of the exposed data. Form submissions often contain personally identifiable information (PII), such as names, email addresses, phone numbers, and potentially more sensitive details depending on the form's purpose. The ability for an unauthenticated actor to enumerate these records constitutes a severe privacy breach and can lead to further attacks such as phishing campaigns or social engineering efforts targeting the exposed individuals. Furthermore, this information disclosure aids attackers in reconnaissance activities by revealing how the organization collects data, what types of forms are active, and potentially identifying key personnel through submission metadata. This level of access undermines the integrity and confidentiality guarantees expected from a secure web application environment.
To mitigate this vulnerability, immediate action is required to update the Convert Forms extension to version 5.2.5 or later, where these access control checks have been properly implemented by the vendor. For organizations unable to patch immediately due to compatibility concerns with other plugins, temporary mitigations should be applied at the web server level. This can include configuring firewalls such as ModSecurity rules to block direct requests to the vulnerable endpoint for unauthenticated users or restricting access based on IP addresses if the submissions are only meant to be viewed from specific internal networks. Additionally, a thorough audit of other custom Joomla extensions is recommended to ensure that similar patterns of improper validation do not exist elsewhere in the codebase, as this type of oversight often indicates broader security hygiene issues within the development process.