CVE-2026-13355 Privilege escalation in Meta Box Frontend Submission
Unauthenticated attackers can escalate privileges to Administrator by exploiting missing authorization checks in Meta Box AIO and related WordPress plugins.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-13355?
CVE-2026-13355 is a critical vulnerability in Meta Box Frontend Submission, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-269
Which versions are affected by CVE-2026-13355?
How do I fix CVE-2026-13355?
No fix has been published for CVE-2026-13355 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-13355 being exploited?
There is no known exploitation of CVE-2026-13355 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-q84q-9hmp-p3qm.