CVE-2026-13407 Overview
CVE-2026-13407 affects the Royal Elementor Addons WordPress plugin in versions before 1.7.1067. The plugin fails to sanitize and escape values submitted through its form widget before embedding them in administrator notification emails. Unauthenticated attackers can inject arbitrary HTML into emails delivered to the site administrator on form submission. The weakness is classified under CWE-116: Improper Encoding or Escaping of Output.
Critical Impact
Unauthenticated attackers can inject arbitrary HTML into administrator notification emails, enabling phishing, credential harvesting, and social engineering against site administrators.
Affected Products
- Royal Elementor Addons WordPress plugin versions prior to 1.7.1067
- WordPress sites using the plugin's form widget to notify administrators
- Publicly reachable WordPress deployments with form submissions enabled
Discovery Timeline
- 2026-09-16 - CVE-2026-13407 published to the National Vulnerability Database
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-13407
Vulnerability Analysis
The Royal Elementor Addons plugin exposes a form widget that site owners embed on public pages. When a visitor submits the form, the plugin builds an HTML email and sends it to the site administrator. User-supplied field values are placed into the email body without proper encoding or escaping. An attacker can therefore submit form fields containing raw HTML, including anchor tags, images, styled elements, or crafted content that mimics legitimate WordPress notifications.
Because the plugin does not require authentication for form submissions, exploitation requires no credentials. The administrator only needs to open the resulting email in a client that renders HTML for the injected markup to display. User interaction on the victim side is required, which limits automated impact but supports targeted phishing.
Root Cause
The root cause is improper output encoding [CWE-116]. The plugin concatenates raw form input into the HTML email body without applying WordPress escaping helpers such as esc_html() or wp_kses(). Any HTML tokens submitted through form fields are treated as markup rather than literal text when the administrator's mail client renders the message.
Attack Vector
An unauthenticated attacker locates a public page hosting the vulnerable form widget. The attacker submits form data with HTML payloads in one or more text fields. The plugin generates a notification email containing the attacker-controlled markup and sends it to the administrator address. When the administrator opens the message, the injected content renders, enabling brand impersonation, malicious links, or embedded tracking pixels. See the WPScan Vulnerability Report for technical details.
Detection Methods for CVE-2026-13407
Indicators of Compromise
- Administrator notification emails containing unexpected HTML elements such as <a>, <img>, <style>, or <script> tags in submitted field values
- Form submissions from external IPs with field content containing angle brackets or URL-encoded HTML entities
- Outbound mail queue entries generated by Royal Elementor Addons with anomalous body sizes
- Reports from administrators of phishing-style content in plugin-generated emails
Detection Strategies
- Inspect web server access logs for POST requests to Royal Elementor Addons form endpoints containing HTML markup in request bodies
- Deploy a Web Application Firewall (WAF) rule to flag form submissions with tags such as <a href, <img src, or <script
- Monitor mail server logs for outbound administrator notifications whose body length or link count deviates from a baseline
Monitoring Recommendations
- Enable verbose logging on WordPress via a security plugin to capture all form submissions and source IP addresses
- Alert on inbound requests targeting Royal Elementor Addons form handlers from addresses outside expected geographies
- Review administrator inboxes for messages that impersonate WordPress, hosting providers, or the plugin vendor
How to Mitigate CVE-2026-13407
Immediate Actions Required
- Upgrade Royal Elementor Addons to version 1.7.1067 or later on all WordPress sites
- Instruct administrators to treat any recent plugin-generated form notification as untrusted and to avoid clicking embedded links
- Audit form widget deployments to identify which sites are exposed and prioritize patching
Patch Information
The vendor has addressed the issue in Royal Elementor Addons version 1.7.1067. The fix introduces proper output encoding for form field values placed into administrator notification emails. Refer to the WPScan Vulnerability Report for advisory details.
Workarounds
- Temporarily disable the Royal Elementor Addons form widget on public pages until the patch is applied
- Configure administrator mail clients to display messages in plain text to neutralize injected HTML rendering
- Route plugin notifications through a mail security gateway that strips or sanitizes HTML from untrusted senders
- Restrict access to form-hosting pages using authentication or IP allow-listing where feasible
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
