CVE-2026-13173 in Eventin Plugin
Summary
by MITRE • 08/19/2026
The Eventin WordPress plugin before 4.1.21 does not verify the current user's permission to edit other users before assigning roles and updating user metadata during speaker creation, allowing users with contributor-level access and above to modify other users' roles and metadata.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/19/2026
The vulnerability identified in Eventin WordPress plugin versions prior to 4.1.21 represents a critical failure in server-side authorization logic, specifically within the mechanism used for creating speakers during event management workflows. This flaw stems from an improper implementation of access control checks when handling user role assignments and metadata updates. In secure software architecture, any operation that modifies sensitive data or alters system state must validate not only the authenticity of the request but also the explicit permission of the authenticated actor to perform that specific action on the target resource. The Eventin plugin fails to enforce this principle by neglecting to verify whether the currently logged-in user possesses administrative privileges or sufficient rights to edit other users before proceeding with role assignment and metadata modification operations.
From a technical perspective, the flaw allows any authenticated user holding at least contributor-level access to escalate their influence within the WordPress environment significantly. By exploiting this lack of verification, an attacker can manipulate the backend logic to assign elevated roles, such as Administrator or Editor, to themselves or other compromised accounts. Furthermore, the ability to update arbitrary user metadata opens avenues for further exploitation, including session hijacking if sensitive fields like authentication keys are modified, or social engineering attacks by altering profile information displayed publicly on the site. This behavior aligns directly with CWE-284, which describes Improper Access Control, and more specifically CWE-639 regarding Authorization Bypass Through User-Controlled Key, as the attacker leverages their existing session to bypass intended restrictions on user management functions.
The operational impact of this vulnerability is severe due to its potential for privilege escalation within a widely used content management system. WordPress sites often host multiple users with varying levels of trust and access rights. A contributor-level account might be expected to have limited capabilities, such as writing posts that require approval. However, the ability to modify other users' roles effectively neutralizes these restrictions, allowing an attacker to gain full control over the website's backend. This can lead to complete site compromise, including defacement, data exfiltration, and the installation of persistent backdoors or malware. Additionally, because WordPress plugins are frequently updated by non-technical administrators who may not immediately patch vulnerabilities, this flaw remains exploitable for extended periods in many deployments, increasing the window of opportunity for malicious actors.
This vulnerability is also relevant to MITRE ATT&CK techniques related to Privilege Escalation and Account Manipulation. Specifically, it mirrors T1078 Valid Accounts where an attacker uses legitimate credentials to gain access, followed by T1098 Unauthorized Access or Modification of Remote Services if the role change allows for further lateral movement in a larger network infrastructure connected to the WordPress instance. The lack of proper authorization checks means that standard security controls relying on user roles are rendered ineffective against this specific attack vector.
To mitigate this risk, immediate action is required by updating the Eventin plugin to version 4.1.21 or later, where these access control validations have been corrected. Administrators should ensure that all plugins and core WordPress installations are kept up-to-date with security patches released by vendors. In environments where automatic updates cannot be immediately applied, implementing a Web Application Firewall can help detect and block anomalous requests targeting user management endpoints, although this is only a temporary compensating control. Regular auditing of user roles and permissions within the WordPress dashboard is also recommended to identify any unauthorized changes that may have occurred prior to patching.