CVE-2026-4302 | WowOptin: Next-Gen Popup Maker <= 1.4.29 - Unauthenticated Server-Side Request Forgery via 'link' Parameter in REST API

The WowOptin: Next-Gen Popup Maker plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.4.29. This is due to the plugin exposing a publicly accessible REST API endpoint (optn/v1/integration-action) with a permission_callback of __return_true that passes user-supplied URLs directly to wp_remote_get() and wp_remote_post() in the Webhook::add_subscriber() method without any URL validation or restriction. The plugin does not use wp_safe_remote_get/post which provide built-in SSRF protection. This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application, which can be used to query and modify information from internal services.

Published: 2026-03-21 Last update: 2026-04-22 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-4302 is rated Low Risk (35.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-4302

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-27 0.05% 0.06% +0.02%
2 2026-03-21 0.05%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-4302

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 2.7 [email protected]

Weakness enumeration for CVE-2026-4302

Affected software / configurations for CVE-2026-4302

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-4302

URL Tags
https://plugins.trac.wordpress.org/browser/optin/tags/1.4.23/frontend/class-rest-frontend.php#L44
https://plugins.trac.wordpress.org/browser/optin/tags/1.4.23/frontend/class-rest-frontend.php#L55
https://plugins.trac.wordpress.org/browser/optin/tags/1.4.23/includes/integrations/implementations/class-webhook.php#L38
https://plugins.trac.wordpress.org/browser/optin/tags/1.4.23/includes/integrations/implementations/class-webhook.php#L45
https://plugins.trac.wordpress.org/browser/optin/trunk/frontend/class-rest-frontend.php#L44
https://plugins.trac.wordpress.org/browser/optin/trunk/frontend/class-rest-frontend.php#L55
https://plugins.trac.wordpress.org/browser/optin/trunk/includes/integrations/implementations/class-webhook.php#L38
https://plugins.trac.wordpress.org/browser/optin/trunk/includes/integrations/implementations/class-webhook.php#L45
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3484392%40optin&new=3484392%40optin&sfp_email=&sfph_mail=
https://www.wordfence.com/threat-intel/vulnerabilities/id/b1c3e480-0221-4913-bcce-f34ded9edca8?source=cve
cvelogic Threat Intelligence