CVE-2026-4302

High

Published: 21 March 2026

Published

21 March 2026

Modified

22 April 2026

KEV Added

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Patch

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CVSS Score 7.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

EPSS Score 0.0009 25.8th percentile

Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-4302 is a high-severity SSRF (CWE-918) vulnerability in Wordpress (inferred from references). Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 25.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 2 other techniques. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

Requires validation of user-supplied URLs before passing them to wp_remote_get() and wp_remote_post() to directly prevent SSRF exploitation.

SI-2 Flaw Remediation good match

prevent

Mandates timely flaw remediation by patching or updating the vulnerable WowOptin plugin versions up to 1.4.29.

AC-4 Information Flow Enforcement good match

prevent

Enforces information flow control policies to restrict the web application from originating requests to arbitrary internal or external locations.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1046 Network Service Discovery Discovery

Adversaries may attempt to get a listing of services running on remote hosts and local network infrastructure devices, including those that may be vulnerable to remote software exploitation.

attack.mitre.org →

T1522 Cloud Instance Metadata API Credential Access

Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.

attack.mitre.org →

Why these techniques?

SSRF in public-facing WordPress plugin directly exploitable via T1190; enables internal network service probing (T1046) and common metadata API access (T1522) for sensitive data.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

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.

Deeper analysisAI

CVE-2026-4302 is a Server-Side Request Forgery (SSRF) vulnerability affecting the WowOptin: Next-Gen Popup Maker plugin for WordPress in all versions up to and including 1.4.29. The issue stems from a publicly accessible REST API endpoint at optn/v1/integration-action, which uses a permission_callback of __return_true, allowing unrestricted access. This endpoint passes user-supplied URLs directly to wp_remote_get() and wp_remote_post() functions within the Webhook::add_subscriber() method without any validation or restrictions, bypassing the SSRF protections offered by wp_safe_remote_get() and wp_safe_remote_post().

Unauthenticated attackers can exploit this vulnerability over the network with low complexity and no user interaction required, achieving a confidential and integrity impact rated at CVSS 7.2 (AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N) under CWE-918. By sending crafted requests to the endpoint, attackers can force the WordPress server to originate web requests to arbitrary internal or external locations, enabling them to query sensitive information from internal services or potentially modify data via POST operations.

References provided in the CVE disclosure point to specific vulnerable code locations in the plugin's source repository, including lines 44 and 55 in frontend/class-rest-frontend.php and lines 38 and 45 in includes/integrations/implementations/class-webhook.php across tags 1.4.23 and the trunk branch. No patch details or mitigation advisories are specified in the available information.