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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-4021 Detail

Description

The Contest Gallery plugin for WordPress is vulnerable to an authentication bypass leading to admin account takeover in all versions up to, and including, 28.1.5. This is due to the email confirmation handler in `users-registry-check-after-email-or-pin-confirmation.php` using the user's email string in a `WHERE ID = %s` clause instead of the numeric user ID, combined with an unauthenticated key-based login endpoint in `ajax-functions-frontend.php`. When the non-default `RegMailOptional=1` setting is enabled, an attacker can register with a crafted email starting with the target user ID (e.g., `[email protected]`), trigger the confirmation flow to overwrite the admin's `user_activation_key` via MySQL integer coercion, and then use the `post_cg1l_login_user_by_key` AJAX action to authenticate as the admin without any credentials. This makes it possible for unauthenticated attackers to take over any WordPress administrator account and gain full site control.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://plugins.trac.wordpress.org/browser/contest-gallery/tags/28.1.4/ajax/ajax-functions-frontend.php#L204 Wordfence
https://plugins.trac.wordpress.org/browser/contest-gallery/tags/28.1.4/v10/v10-admin/users/frontend/registry/users-registry-check-after-email-or-pin-confirmation.php#L153 Wordfence
https://plugins.trac.wordpress.org/browser/contest-gallery/trunk/ajax/ajax-functions-frontend.php#L204 Wordfence
https://plugins.trac.wordpress.org/browser/contest-gallery/trunk/v10/v10-admin/users/frontend/registry/users-registry-check-after-email-or-pin-confirmation.php#L153 Wordfence
https://plugins.trac.wordpress.org/changeset?old_path=/contest-gallery/tags/28.1.5&new_path=/contest-gallery/tags/28.1.6 Wordfence
https://www.wordfence.com/threat-intel/vulnerabilities/id/f1b9725b-dee5-44ca-bb33-c6812fb76adc?source=cve Wordfence

Weakness Enumeration

CWE-ID CWE Name Source
CWE-287 Improper Authentication Wordfence  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-4021
NVD Published Date:
03/23/2026
NVD Last Modified:
03/23/2026
Source:
Wordfence