CVE-2026-13355

Critical

Description

The Meta Box AIO plugin for WordPress is vulnerable to Privilege Escalation to Administrator in versions up to, and including, 3.11.0. This is due to a chained flaw: the populate_via_query_string() function in the mb-frontend-submission component unconditionally overrides the form's target object_id from the GET parameter 'rwmb_frontend_field_object_id' without any authorization check, and Form::process() lacks the user_can_edit() check present in render(), allowing unauthenticated attackers to overwrite the post_content of any page with an arbitrary shortcode via wp_update_post(); the mb-user-profile component then directly trusts the 'role' and 'auto_login' shortcode attributes in the injected [mb_user_profile_register] shortcode with no role validation. This makes it possible for unauthenticated attackers to elevate their privileges to Administrator. The standalone plugins Meta Box Frontend Submission (in versions up to 4.5.6) and Meta Box User Profile (versions up to 3.11.0) are also affected.

SeverityCritical
CVSS9.8
Exploit probability—
ProductMeta Box Frontend Submission
PublishedSep 22, 2026
First seenSep 22, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
Meta Box Meta Box Frontend Submissionv ≤ 4.5.6—

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