CVE-2026-4003

CRITICAL EPSS 54.8%
Published Apr 8, 20262mo ago · Modified Jun 17, 20262w ago
9.8 CVSS 3.1
Critical
Find Similar
Published Apr 8, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
9.8
Exploitability
3.9
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
54.8% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-862 Missing Authorization Authorization

References 12

  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L186
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L190
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L233
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-common.php#L168
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-functions-user.php#L235
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L186
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L190
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L233
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-common.php#L168
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-functions-user.php#L235
  • plugins.trac.wordpress.org https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3491109%40userspn&new=3491109%40userspn&sfp_email=&sfph_mail=
  • wordfence.com https://www.wordfence.com/threat-intel/vulnerabilities/id/27bb60c1-43fa-4a18-b9ca-059535b0d5b6?source=cve

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.