CVE-2026-9834

The WP Database Backup – Unlimited Database & Files Backup by Backup for WP plugin for WordPress is vulnerable to OS Command Injection in all versions up to and including 7.11 via the wp_db_exclude_table parameter. This is due to the direct concatenation of user-supplied $_POST['wp_db_exclude_table'] values into the mysqldump shell command string in the mysqldump() function of includes/admin/class-wpdb-admin.php without wrapping them in escapeshellarg()—every other argument in the same command (DB_USER, DB_PASSWORD, host, filename, DB_NAME) is properly escaped, making the exclude-table values the sole exception—and because the only applied filtering, sanitize_text_field() via recursive_sanitize_text_field(), strips HTML tags but leaves shell metacharacters such as ;, |, `, and $() intact. This makes it possible for authenticated attackers, with administrator-level access and above, to execute arbitrary operating system commands on the server, potentially enabling full remote code execution. The injection is stored: malicious values submitted through the plugin settings form are persisted to the WordPress options table via update_option('wp_db_exclude_table') and later retrieved with get_option() and passed unsanitized to shell_exec() whenever a backup operation runs.