CVE-2026-16149
Security Hardener <= 2.4.4 - Authenticated (Subscriber+) Privilege Escalation via REST API '/wp/v2/users' permission_callback Overwrite
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.8
Security Hardener <= 2.4.4 - Authenticated (Subscriber+) Privilege Escalation via REST API '/wp/v2/users' permission_callback Overwrite
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.
- Record
CVE-2026-16149- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-269
- Updated
- 2026-11-02
EUVDEUVD-2026-64605
8.8
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.
- Record
EUVD-2026-64605- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-493r-g3qv-5457
8.8
The Security Hardener plugin for WordPress is vulnerable to Missing Authorization in all versions...
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.
- Record
GHSA-493r-g3qv-5457- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-269
- Updated
- 2026-11-02
NVD
8.8
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.
- Record
CVE-2026-16149- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-269
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-16149 is a high vulnerability (CVSS 8.8) in Marc4 Security Hardener, published August 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.59%, the 48th percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/64f1a71f-e210-4191-bfb4-56f8568180ed?source=cve
plugins.trac.wordpress.org/browser/security-hardener/tags/2.4.4/security-hardener.php
plugins.trac.wordpress.org/changeset/3630896/security-hardener
nvd.nist.gov/vuln/detail/CVE-2026-16149
github.com/advisories/GHSA-493r-g3qv-5457