CVE-2026-86832 in MetForm Plugin
Summary
by MITRE • 10/03/2026
The MetForm WordPress plugin before 4.3.1 does not properly restrict access to form submission data, allowing unauthenticated attackers to view submitter information through the REST API.
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Analysis
by VulDB Data Team • 10/03/2026
The vulnerability identified in versions of the MetForm WordPress plugin prior to release 4.3.1 represents a critical failure in access control mechanisms within the application's architecture. Specifically, the flaw resides in how the plugin handles requests directed at its internal REST API endpoints designed for processing form submissions. In a secure implementation, any endpoint that exposes sensitive user data must enforce strict authentication checks and authorization policies to ensure that only authorized administrators or users with specific permissions can access such information. However, in this instance, the developers failed to implement adequate restrictions on these submission-related routes, leaving them accessible to unauthenticated actors without requiring valid credentials or session tokens.
From a technical perspective, this misconfiguration allows remote attackers to interact directly with the REST API endpoints responsible for retrieving form data. By sending crafted HTTP requests to these unprotected paths, an attacker can bypass standard WordPress security layers that typically protect administrative functions and private content. The vulnerability effectively turns what should be a protected internal communication channel into a publicly accessible information disclosure vector. This lack of enforcement means that any individual on the internet with knowledge of the endpoint structure or through automated scanning tools can query the system to extract data associated with previous form submissions, such as names, email addresses, and other personally identifiable information entered by legitimate users.
The operational impact of this vulnerability is significant due to the nature of the exposed data. Form submission plugins are commonly used for contact forms, registration processes, lead generation, and customer support requests, all of which involve collecting sensitive personal details from website visitors. The unauthorized exposure of submitter information constitutes a severe privacy breach and can lead to consequences such as identity theft, phishing campaigns targeting affected individuals, or unsolicited spam attacks against the exposed email addresses. Furthermore, this data leakage undermines user trust in the website owner's ability to protect their audience's private information, potentially resulting in reputational damage and non-compliance with data protection regulations like GDPR or CCPA depending on the jurisdiction of the users involved.
This vulnerability aligns closely with CWE-284, which describes Improper Access Control, as it involves a failure to restrict access to resources for unauthorized actors. Additionally, from an offensive security perspective, this flaw facilitates information gathering and data exfiltration, mapping directly to techniques found in the MITRE ATT&CK framework such as API Abuse or Collection of Application Data through unauthenticated endpoints. The attack vector is classified as remote with no prerequisites for authentication, making it highly exploitable by automated bots scanning thousands of WordPress installations daily.
To mitigate this risk, site administrators must immediately update the MetForm plugin to version 4.3.1 or later, where these access control restrictions have been properly implemented. Until an upgrade can be performed, temporary mitigations include restricting access to the wp-admin directory and any known REST API endpoints associated with the plugin via web application firewall rules if possible, although this is less effective than a patch since specific endpoint paths may vary. It is also advisable to audit other installed plugins for similar misconfigurations in their REST API implementations to ensure comprehensive security posture across the WordPress environment. Regular maintenance and keeping all components up to date remain the most effective defense against such common configuration flaws prevalent in widely used content management system extensions.