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Vulnerabilities

Vulnerability · CVE-2026-4003

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.

Published Apr 8, 2026 · catalog updated Oct 13, 2026 · Félix Martínez Users manager – PN

Severity
Critical9.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
1.3%
Remediation
Remediation guidance
Affected products
vendor Félix Martínez Users manager – PN

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.

Technical analysis

Mechanism and impact are interpreted from ingested advisories — not independent exploit research.

  • CWE classification

    Missing Authorization

  • Prerequisites and impact

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

How to fix CVE-2026-4003

What to do

Three reads of the same public record: the decision, the versions on file, and the signals. Confirm the vendor advisory before you patch. This page does not publish exploit steps.

Executive

Treat this as an active risk. CVE-2026-4003 is a critical issue in Félix Martínez Users manager – PN (CVSS 9.8). CISA lists it as known exploited since Oct 13, 2026. Next step: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

System administrator

Check whether Félix Martínez Users manager – PN is installed. Ranges on record: Félix Martínez Users manager – PN. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Security analyst

CVSS 9.8. EPSS 1.3%. CISA lists it as known exploited since Oct 13, 2026. Weaknesses: CWE-862. Sources: cve_org, epss, nvd, vulncheck_kev. Exploit links, when listed below, point at the original publisher.

Related intelligence

  • Exploitation evidence

    Confirmed in CISA KEV since Oct 13, 2026. Listed in CISA KEV and VulnCheck KEV.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Technology hubs

WordPress security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 8, 2026 · NIST NVD

    Detected

    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 su

  2. Jul 24, 2026 · NIST NVD

    Updated

    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 su

  3. Oct 13, 2026 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

  4. Oct 13, 2026 · VulnCheck KEV

    Updated

    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 su

Affected versions

Enter an installed version to get a verified affected / not-affected result against the ranges below.

  • vendor Félix Martínez Users manager – PNversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-4003

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-4003

    30-day exploitation probability 1.3%

    first.org
  • NIST NVDVulnerability recordCVE-2026-4003

    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_sav

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2026-4003

    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_sav

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.