CVE-2026-4003
Users manager – PN <= 1.1.15 - Unauthenticated Privilege Escalation via Account Takeover via 'userspn_form_save' AJAX Action
Description
The Users manager – PN plugin for WordPress is vulnerable to Privilege Escalation via Arbitrary User Meta Update in all versions up to and including 1.1.15. This is due to a flawed authorization logic check in the userspn_ajax_nopriv_server() function within the 'userspn_form_save' case. The conditional only blocks unauthenticated users when the user_id is empty, but when a non-empty user_id is supplied, execution bypasses this check entirely and proceeds to update arbitrary user meta via update_user_meta() without any authentication or authorization verification. Additionally, the nonce required for this AJAX endpoint ('userspn-nonce') is exposed to all visitors via wp_localize_script on the public wp_enqueue_scripts hook, rendering the nonce check ineffective as a security control. This makes it possible for unauthenticated attackers to update arbitrary user metadata for any user account, including the userspn_secret_token field.
INFO
Published Date :
April 8, 2026, 5:16 a.m.
Last Modified :
April 8, 2026, 5:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-4003
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update the Users Manager – PN plugin to the latest version.
- Remove the plugin if it is not needed.
- Apply vendor-provided patches or updates.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-4003.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-4003 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-4003
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-4003 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-4003 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Apr. 08, 2026
Action Type Old Value New Value Added Description The Users manager – PN plugin for WordPress is vulnerable to Privilege Escalation via Arbitrary User Meta Update in all versions up to and including 1.1.15. This is due to a flawed authorization logic check in the userspn_ajax_nopriv_server() function within the 'userspn_form_save' case. The conditional only blocks unauthenticated users when the user_id is empty, but when a non-empty user_id is supplied, execution bypasses this check entirely and proceeds to update arbitrary user meta via update_user_meta() without any authentication or authorization verification. Additionally, the nonce required for this AJAX endpoint ('userspn-nonce') is exposed to all visitors via wp_localize_script on the public wp_enqueue_scripts hook, rendering the nonce check ineffective as a security control. This makes it possible for unauthenticated attackers to update arbitrary user metadata for any user account, including the userspn_secret_token field. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-862 Added Reference https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L186 Added Reference https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L190 Added Reference https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L233 Added Reference https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-common.php#L168 Added Reference https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-functions-user.php#L235 Added Reference https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L186 Added Reference https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L190 Added Reference https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L233 Added Reference https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-common.php#L168 Added Reference https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-functions-user.php#L235 Added Reference https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3491109%40userspn&new=3491109%40userspn&sfp_email=&sfph_mail= Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/27bb60c1-43fa-4a18-b9ca-059535b0d5b6?source=cve