CVE-2026-4031: Authorization Bypass in Database Backup for WordPress

Successful exploitation of CVE-2026-4031 allows an attacker to intercept database backup files created by the plugin. These backups often contain sensitive data, including user credentials, database schemas, and application configuration details. By controlling the wpdbtemp_dir parameter, an attacker can dictate where these backups are written, choosing a publicly accessible location like the wp-content/uploads/ directory. The predictable naming convention of the backup files makes interception relatively straightforward. This could lead to complete compromise of a WordPress site and its associated data, similar to scenarios where attackers have exploited misconfigured file storage locations to steal sensitive information.

1. 予約済み2026-03-12
2. 公開日2026-05-14

The primary mitigation for CVE-2026-4031 is to immediately upgrade the Database Backup for WordPress plugin to version 2.5.3 or later. If upgrading is not immediately feasible due to compatibility issues or breaking changes, consider restricting access to the wpdbtempdir directory. Implement strict file permissions, ensuring that only the webserver user has write access. Additionally, monitor the wp-content/uploads/ directory and other potential public locations for unexpected files with predictable naming patterns. While not a direct fix, a Web Application Firewall (WAF) could be configured to block requests containing suspicious values for the wpdbtempdir parameter. After upgrading, verify the fix by manually triggering a database backup and confirming that the backup file is not accessible from a web browser.