CVE-2026-92226 in Joomla
Summary
by MITRE • 09/29/2026
Joomla! Core - [20260913] - Core - Improper ACL checks for varous webservice edit tasks in Joomla 4.0.0-5.4.8, 6.0.0-6.1.3 - An improper access check allows unauthorized users to perform edit actions on otherwise uneditable items.
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability identified as CVE-20260913 represents a critical failure in the Access Control List (ACL) enforcement mechanisms within the Joomla! content management system, specifically affecting versions 4.0.0 through 5.4.8 and 6.0.0 through 6.1.3. This flaw is rooted in the core web service layer of the application, which serves as the primary interface for programmatic interactions with site data via RESTful APIs or similar endpoints. In a properly secured environment, these services must rigorously validate that the authenticated user possesses the necessary permissions to modify specific content items before executing any write operations. However, due to improper ACL checks within various edit tasks exposed through this web service layer, the system fails to correctly verify authorship or administrative privileges for certain entities. This architectural oversight allows an attacker who has valid authentication credentials with lower-level access rights, such as a registered user or editor without global admin permissions, to bypass intended restrictions and modify content that should be immutable by their role.
From a technical perspective, the root cause lies in how the web service controllers handle permission inheritance and scope validation during edit operations. When an API request is received to update a record, the framework must cross-reference the user's group hierarchy against the specific access levels assigned to the target item or component section. In this instance, the logic governing these checks contains gaps where certain fields or entire entities are not subjected to sufficient scrutiny regarding ownership and modification rights. Consequently, an authenticated attacker can craft malicious API requests that exploit these logical flaws to alter database records outside their authorized scope. This is particularly dangerous because web services often operate with higher trust assumptions than standard browser-based interactions, relying on the integrity of the authentication token rather than continuous session validation or complex UI-based safeguards. The vulnerability effectively transforms a low-privilege account into a tool for unauthorized data manipulation, undermining the fundamental principle of least privilege that underpins modern application security architectures.
The operational impact of this vulnerability is severe, as it directly compromises the confidentiality and integrity of the website's content management system. Attackers can use this flaw to deface web pages by injecting malicious code or misleading information into articles, banners, or other editable components. Beyond simple vandalism, this access bypass facilitates more sophisticated attacks such as privilege escalation if certain configuration settings are stored in accessible entities, or data exfiltration if the modified content triggers specific backend processes that leak sensitive information. Furthermore, because Joomla! is widely used for e-commerce and corporate websites, an attacker could alter product descriptions, pricing structures, or customer-facing messages to facilitate social engineering attacks or financial fraud. The ability to edit uneditable items also disrupts audit trails and compliance reporting, as changes made through this vulnerability may not be properly attributed to the correct user role in system logs if the logging mechanism relies on the same flawed permission checks.
This flaw aligns with CWE-269, Improper Privilege Management, where a software application does not assign appropriate privileges or permissions for specific operations and contexts. It also maps closely to MITRE ATT&CK technique T1078, Valid Accounts, as it involves using legitimate credentials to perform unauthorized actions that are typically restricted by role-based access controls. Additionally, the exploitation of web service endpoints places this vulnerability within the context of API security failures often categorized under CWE-923, Improper Restriction of Excessive Authentication Attempts or more broadly under improper input validation and authorization checks in RESTful APIs. The persistence of such flaws across multiple major versions indicates a systemic issue in how Joomla! core developers implement permission boundaries for its programmatic interfaces, highlighting the need for rigorous code review focused on access control logic rather than just functional correctness.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. For administrators running affected versions, upgrading to the latest patched release of Joomla web services, ensuring they do not inadvertently expose additional endpoints or bypass core ACL checks through poorly implemented helper functions. Regular penetration testing focused on API authorization flows is essential to identify similar logical flaws before they can be exploited in production environments.