CVE-2026-19699 in GutenKit Plugin
Summary
by MITRE • 08/20/2026
The GutenKit WordPress plugin before 2.5.0 does not have a sufficient capability check on some of its REST API endpoints, allowing users with the Contributor role and above to retrieve mailing-list audience metadata from the site's connected marketing account.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in GutenKit versions prior to 2.5.0 represents a critical authorization flaw within the plugin’s integration with external marketing services via REST API endpoints. This issue stems directly from an insufficient capability check, which is a common category of access control errors where software fails to properly verify that a user has the necessary permissions before executing sensitive operations or exposing data. In this specific instance, the developers did not implement robust server-side validation for certain administrative functions exposed through the application programming interface. Consequently, any authenticated user possessing at least the Contributor role on the WordPress installation can interact with these endpoints without triggering an authorization failure. This architectural oversight allows lower-privileged users to bypass intended restrictions and access data that should be reserved for higher-level administrators or specific marketing personnel roles.
The operational impact of this vulnerability is significant due to the nature of the exposed information, which includes mailing-list audience metadata from a site’s connected marketing account. Mailing lists often contain personally identifiable information such as email addresses, subscriber names, and potentially other demographic data collected through website interactions. The exposure of this metadata can lead to privacy violations and potential non-compliance with data protection regulations like GDPR or CCPA if the data is considered personal information under those jurisdictions. Furthermore, attackers could use this aggregated audience data for targeted phishing campaigns, social engineering attacks, or competitive intelligence gathering. By understanding who subscribes to a site’s newsletter, an attacker can craft more convincing malicious communications aimed at specific segments of that audience, thereby increasing the likelihood of successful credential theft or malware delivery against individual subscribers.
From a technical classification perspective, this vulnerability aligns with CWE-284 Improper Access Control and specifically CWE-915 Improvement to Improve Incorrectly Controlled Modification of Dynamically-Determined Object Attributes if the data retrieval involves modifying state, though it primarily fits CWE-732 in terms of exposing sensitive information through improper access controls. In the context of the MITRE ATT&CK framework for enterprise security, this behavior maps to T1087 Account Discovery and potentially T1539 Steal Web Session Cookie if session tokens are also inadvertently exposed during these requests. The lack of proper role-based access control enforcement means that the principle of least privilege is violated, allowing users with minimal privileges to perform actions typically reserved for system administrators or specialized marketing managers who require such data for legitimate business operations.
Mitigation strategies must focus on immediate remediation and long-term security hardening. For organizations currently running GutenKit versions earlier than 2.5.0, the primary recommendation is to upgrade immediately to version 2.5.0 or later where this capability check has been corrected by the developers. Until an update can be applied, administrators should consider disabling REST API access for non-essential endpoints if possible through server-level configurations or security plugins that allow granular control over API routes. Additionally, implementing strict role-based permissions within WordPress to ensure that only users with Administrator privileges have access to marketing integrations is advisable. Regular auditing of plugin code and adherence to secure coding standards during development can prevent similar authorization flaws in future updates. Security teams should also monitor logs for unusual REST API activity originating from low-privilege accounts, as this may indicate exploitation attempts against other unpatched vulnerabilities within the same ecosystem.