CVE-2026-9834

CVE-2026-9834 is a high-severity vulnerability with a CVSS 3.x base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-77.

Key facts

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-9834?
CVE-2026-9834 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-9834 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-9834?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-9834 published?
CVE-2026-9834 was published on 2026-07-02.

References

Other CWE-77 (Command Injection) vulnerabilities

Browse all CWE-77 (Command Injection) vulnerabilities →