CVE-2026-84901 in Eventin Plugin
Summary
by MITRE • 09/05/2026
The Eventin WordPress plugin before 4.1.22 does not properly check authorization on several of its event-management REST routes, allowing users with contributor-level access and above to change the site's front-page setting to an event they do not own and to create, edit and delete global event and speaker taxonomy terms they should not be able to manage.
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Analysis
by VulDB Data Team • 09/05/2026
The vulnerability identified in Eventin WordPress plugin versions prior to 4.1.22 represents a critical failure in access control mechanisms within the application's REST API implementation. This flaw stems from insufficient authorization checks on several event-management endpoints, which are designed to handle sensitive administrative and editorial tasks. In a properly secured system, any request modifying state or accessing restricted resources must verify that the authenticated user possesses the necessary privileges for that specific action. However, in this instance, the plugin fails to validate whether the requesting contributor-level user has ownership of the target event or permission to modify global taxonomy terms. This oversight allows users with relatively low privilege levels, such as contributors who typically have limited editing rights restricted to their own posts, to escalate their effective permissions significantly by interacting directly with these unprotected API routes.
The technical nature of this flaw is classified under CWE-284, Improper Access Control, and aligns with the ATT&CK technique T1078, Valid Accounts, as it allows an authenticated user to perform actions beyond their assigned role. Specifically, the vulnerability enables a contributor-level attacker to manipulate the site's front-page setting by assigning an event they do not own to this prominent position. This action can disrupt the website's primary user experience and potentially mislead visitors if the selected event is inappropriate or unauthorized. Furthermore, the lack of authorization checks extends to global taxonomy management for events and speakers. Contributors are able to create, edit, and delete these terms globally, which affects all users and content on the site rather than just their own contributions. This capability undermines the integrity of the website's organizational structure and metadata, allowing an attacker to inject malicious or misleading information into categories that may be used across multiple posts by other authors with higher privileges.
The operational impact of this vulnerability is substantial due to its potential for privilege escalation and data manipulation. By exploiting these REST endpoints, a contributor can effectively assume roles typically reserved for editors or administrators without needing valid credentials for those higher-level accounts. This could lead to defacement of the website's front page, corruption of event listings through unauthorized deletion or modification of speaker information, and general disruption of site functionality. In environments where multiple users contribute content, such as news outlets or community platforms, this vulnerability poses a significant risk to data integrity and trustworthiness. An attacker with contributor access could systematically alter global settings or taxonomy terms, causing widespread confusion for end-users and potentially damaging the reputation of the organization hosting the WordPress site.
Mitigation strategies must focus on immediate patching and rigorous validation of API endpoints. The primary remediation is to upgrade the Eventin plugin to version 4.1.22 or later, where these authorization checks have been properly implemented to ensure that users can only modify resources they own or are explicitly permitted to manage. In addition to updating the software, administrators should review their user role configurations and consider implementing additional security plugins that enforce stricter REST API access controls. It is also advisable to audit existing contributor accounts for any suspicious activity prior to patching, as an attacker may have already exploited this flaw during the window of vulnerability. Regularly monitoring WordPress core updates and plugin changelogs is essential to maintain a secure posture against such authorization bypass vulnerabilities.