CVE-2026-15827 Missing authorization in GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor

What is CVE-2026-15827?

CVE-2026-15827 is a medium-severity missing authorization vulnerability in ataurr GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The GutenKit Blocks plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the /wp-json/gutenkit/v1/mailchimp/get/lists and /wp-json/gutenkit/v1/mailchimp/get/interests REST API endpoints in versions up to, and including, 2.4.12. Both endpoints are registered with permission_callback => '__return_true', and their callbacks read the site's stored Mailchimp API key from the gutenkit_settings_list option and proxy Mailchimp audience/list, merge-field, interest-category, interest-name, and subscriber-count metadata back to the caller with no login, nonce, or capability check. This makes it possible for unauthenticated attackers to retrieve private Mailchimp audience configuration information from any site that has configured the GutenKit Mailchimp integration.

Weakness: CWE-862

Which versions are affected by CVE-2026-15827?

How do I fix CVE-2026-15827?

No fix has been published for CVE-2026-15827 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-15827 being exploited?

There is no known exploitation of CVE-2026-15827 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-phq4-ggcm-gj84.