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.

• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/wp-database-backup/tags/7.10/includes/admin/class-wpdb-admin.php#L216
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/wp-database-backup/tags/7.10/includes/admin/class-wpdb-admin.php#L2644
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/wp-database-backup/tags/7.10/includes/admin/class-wpdb-admin.php#L2654
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/wp-database-backup/tags/7.11/includes/admin/class-wpdb-admin.php#L216
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/wp-database-backup/tags/7.11/includes/admin/class-wpdb-admin.php#L2644
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/wp-database-backup/tags/7.11/includes/admin/class-wpdb-admin.php#L2654
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3574273%40wp-database-backup&new=3574273%40wp-database-backup&sfp_email=&sfph_mail=
• www.wordfence.comhttps://www.wordfence.com/threat-intel/vulnerabilities/id/0a97a217-b00b-4268-a472-8d62ae1d18e3?source=cve