CVE-2026-4003
Vulnérabilité critique dans Users manager – PN (felixmartinez)
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.
Gravité et risque d'exploitation
CVE-2026-4003 obtient un score CVSS de 9.8/10, soit une gravité critique. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 1.31 %, ce qui la place devant 70.3 % des CVE référencées.
Que faire ?
- Vérifiez si Users manager – PN (versions 0, <=1.1.15) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://www.wordfence.com/threat-intel/vulnerabilities/id/27bb60c1-43fa-4a18-b9ca-059535b0d5b6?source=cve
- https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L233
- https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L233
- https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L186
- https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L186
- https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L190
- https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L190
- https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-common.php#L168
- https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-common.php#L168
- https://plugins.trac.wordpress.org/browser/userspn/trunk/includes/class-userspn-functions-user.php#L235
- https://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-functions-user.php#L235
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3491109%40userspn&new=3491109%40userspn&sfp_email=&sfph_mail=
