CVE-2026-16149 Missing authorization in Security Hardener
Authenticated subscribers can escalate privileges to Administrator by exploiting missing authorization checks in the Security Hardener plugin's REST API handlers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-16149?
CVE-2026-16149 is a high-severity missing authorization vulnerability in marc4 Security Hardener, published on 22 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The Security Hardener plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 2.4.4. The vulnerability exists because the plugin's user-enumeration protection, which is enabled by default, hooks the rest_endpoints filter via secure_user_endpoints() and overwrites every registered handler's permission_callback on both the /wp/v2/users and /wp/v2/users/(?P<id>[\d]+) routes — including POST, PUT, PATCH, and DELETE handlers — with a bare closure that returns only is_user_logged_in(), completely stripping WordPress Core's original capability checks such as create_users, promote_user, edit_users, and delete_users that WP_REST_Users_Controller normally enforces. This makes it possible for authenticated attackers with Subscriber-level access and above to create new Administrator accounts by sending POST request to /wp/v2/users with administrator role, or to reset an existing Administrator's password by issuing a PUT/POST request to /wp/v2/users/<id>. Because the block_user_enum option defaults to enabled, no special plugin configuration is required — the overwrite is active on every request as soon as the plugin is installed.
Weakness: CWE-269
Which versions are affected by CVE-2026-16149?
How do I fix CVE-2026-16149?
No fix has been published for CVE-2026-16149 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-2026-16149 being exploited?
There is no known exploitation of CVE-2026-16149 in the wild and no public exploit code.
Sources
Also known as GHSA-493r-g3qv-5457.