Canto <= 3.1.1 — Missing Authorization to Authenticated (Subscriber+) Arbitrary Setting Modification

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Canto.
• No admin access? Run a passive check of your site. It reads public files only.

What to do

1. Update to version 3.1.2, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch Canto to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Legion Hunter.

The Canto plugin for WordPress is vulnerable to Missing Authorization in versions up to and including 3.1.1. This is due to the absence of any capability check or nonce verification in the updateOptions() function, which is exposed via two AJAX hooks: wp_ajax_updateOptions (class-canto.php line 231) and wp_ajax_fbc_updateOptions (class-canto-settings.php line 76). Both hooks are registered exclusively under the wp_ajax_ prefix (requiring only a logged-in user), with no call to current_user_can() or check_ajax_referer(). This makes it possible for authenticated attackers with subscriber-level access and above to arbitrarily modify or delete plugin options controlling cron scheduling behavior (fbc_duplicates, fbc_cron, fbc_schedule, fbc_cron_time_day, fbc_cron_time_hour, fbc_cron_start) and to manipulate or clear the plugin's scheduled WordPress cron event (fbc_scheduled_update).

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

• Advisorywordfence.com

Related CVEs

Timeline

1. Apr 16, 2026

   CVE published

   Severity medium, CVSS 4.3

2. Nov 13, 2026

   Record last updated