CVE-2026-4003 json
Users manager – PN <= 1.1.15 - Unauthenticated Privilege Escalation via Account Takeover via 'userspn_form_save' AJAX Action
published 2026-04-08 7 mo ago modified 2026-07-24 3 mo ago also EUVD-2026-20043
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 60%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 7 mo ago
Exploit prediction
0.91% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- felixmartinez Users manager – PN
Classification
- Weakness
-
- CWE-862 Missing Authorization
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/27bb60c1-43fa-4a18-b9ca-059535b0d5b6?source=cve
- plugins.trac.wordpress.org /browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L233
- plugins.trac.wordpress.org /browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L233
- plugins.trac.wordpress.org /browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L186
- plugins.trac.wordpress.org /browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L186
- plugins.trac.wordpress.org /browser/userspn/trunk/includes/class-userspn-ajax-nopriv.php#L190
- plugins.trac.wordpress.org /browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L190
- plugins.trac.wordpress.org /browser/userspn/trunk/includes/class-userspn-common.php#L168
- plugins.trac.wordpress.org /browser/userspn/tags/1.0.31/includes/class-userspn-common.php#L168
- plugins.trac.wordpress.org /browser/userspn/trunk/includes/class-userspn-functions-user.php#L235
- plugins.trac.wordpress.org /browser/userspn/tags/1.0.31/includes/class-userspn-functions-user.php#L235
- plugins.trac.wordpress.org /changeset?sfp_email=&sfph_mail=&reponame=&old=3491109%40userspn&new=3491109%40userspn&sfp_email=&sfph_mail=
Sources
- CVE List CVE-2026-4003
- NVD CVE-2026-4003
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.