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Fencer Vulns
high 8.8

CVE-2026-16149 json

Security Hardener <= 2.4.4 - Authenticated (Subscriber+) Privilege Escalation via REST API '/wp/v2/users' permission_callback Overwrite

published 2026-08-22 2 mo ago modified 2026-10-12 27 d ago also EUVD-2026-64605

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

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.

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 mo ago

Exploit prediction

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • marc4 Security Hardener

Classification

Weakness
  • CWE-269 Improper Privilege Management
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.