CVE-2026-6441: 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 capabil...

Description

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).

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

0.28%

19.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

References

Timeline

Published: Apr 17, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-6441?

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).

How severe is CVE-2026-6441?

CVE-2026-6441 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.28% probability of exploitation in the next 30 days.

How do I fix CVE-2026-6441?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.