WordPress security changelog
MEDIUM CVE-2026-6441 Deferred

Canto: A security weakness

Canto is affected by a security weakness. Exploitation requires at least subscriber-level access. The resulting impact depends on how the affected component exposes the vulnerable operation. The published affected range is <= 3.1.1.

CVE / CNA score 4.3 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Canto
Plugin slug
canto
Affected
<= 3.1.1
Safe version
> 3.1.1
Published
Apr 17, 2026
Weakness
CWE-862 — Missing Authorization

This CVE was published Apr 17, 2026 and is one of 9 known issues for this plugin.

What to do

Update, patch or deactivate.

Update Canto to a release after 3.1.1, or disable and remove it until a fixed version is available.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical 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).

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

References

Primary and upstream sources