CSRF in Sphex1987 Wp Responsive Popup + Optin
CVE-2026-4131
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.
Vulnerability class: CSRF (Cross-Site Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (11.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 11.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Sphex1987 Wp Responsive Popup + Optin — versions 0
Weakness classification (CWE)
References
- www.wordfence.com/threat-intel/vulnerabilities/id/0a8a49c4-21e8-447c-94da-8241c…
- plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php
- plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php
- plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php
- plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php
- plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wp-popup-optin.php
- plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wp-popup-optin.php
- plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php
- plugins.trac.wordpress.org/browser/wp-popup-optin/tags/1.4/wpo_admin_page.php
- plugins.trac.wordpress.org/browser/wp-popup-optin/trunk/wpo_admin_page.php
Frequently asked questions
- What is CVE-2026-4131?
- CVE-2026-4131 is a medium-severity vulnerability in Sphex1987 Wp Responsive Popup + Optin, classified under Cross-Site Request Forgery (CSRF). CVSS score: 6.1/10. Published 2026-04-22.
- How severe is CVE-2026-4131?
- Medium severity. CVSS v3 base score is 6.1 out of 10.