CVE-2026-28189 in Participants Database Plugin
Summary
by MITRE • 08/13/2026
Unauthenticated Arbitrary File Deletion in Participants Database <= 2.7.8.4 versions.
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Analysis
by VulDB Data Team • 08/13/2026
This vulnerability exists in the Participants Database plugin for WordPress systems where unauthenticated attackers can delete arbitrary files from the server through a flaw in the plugin's handling of file operations. The issue affects versions up to and including 2.7.8.4, making it a significant concern for thousands of WordPress installations that have not updated their plugins. The vulnerability stems from insufficient input validation and authentication checks within the plugin's file deletion functionality, allowing any remote user to exploit this weakness without requiring valid credentials or administrative privileges.
The technical implementation of this flaw occurs when the plugin processes file deletion requests through a vulnerable endpoint that does not properly verify whether the request originates from an authenticated administrator. Attackers can construct malicious requests that specify file paths on the server and trigger deletion operations, potentially targeting critical system files, plugin files, theme files, or even user data. This type of vulnerability is categorized as CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which falls under the broader category of path traversal attacks where attackers can manipulate file system access through improper validation of user-supplied input.
The operational impact of this vulnerability extends beyond simple file deletion, as it provides attackers with a powerful foothold for further compromise. Successful exploitation can lead to complete system takeover by deleting core WordPress files, database connection scripts, or configuration files that would render the website inaccessible. Additionally, attackers could target backup files, log files, or other sensitive data stored within the web root directory. This vulnerability aligns with ATT&CK technique T1078 - Valid Accounts and T1499 - Endpoint Denial of Service, as it enables unauthorized access to system resources and can cause service disruption through deletion of critical components.
Organizations should immediately update their Participants Database plugin to version 2.7.8.5 or later, which contains the necessary patch for this vulnerability. The mitigation strategy involves implementing proper authentication checks and input validation for all file operations within the plugin. Security teams should also monitor their systems for any unauthorized file deletions or unusual access patterns that might indicate exploitation attempts. Network-level protections such as web application firewalls can help detect and block malicious requests targeting known vulnerable endpoints, while regular security audits of installed plugins can identify other potential vulnerabilities in the WordPress ecosystem. The patch addresses the root cause by enforcing proper authentication checks before allowing any file deletion operations, ensuring that only authorized administrators can perform such critical actions within the system.