CVE-2026-18409
Received Received - Intake

Stored XSS in WPForms Pro WordPress Plugin

Publication date: 2026-08-21

Last updated on: 2026-08-21

Assigner: Wordfence

Description
The WPForms Pro plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Single Line Text and Paragraph Text Field Values in all versions up to, and including, 2.0.0.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit relies on the plugin's own wp_kses_allowed_html filter widening the 'post' allowlist to permit iframe elements with a data-src attribute, which is not on WordPress's URI-attribute sanitization list, allowing a javascript: URI stored in data-src to survive kses processing and subsequently be promoted to a live src attribute by the bundled admin script view-entry.min.js.

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Meta Information

Published
2026-08-21
Last Modified
2026-08-21
Generated
2026-08-21
AI Q&A
2026-08-21
EPSS Evaluated
N/A
NVD
CVE-2026-18409
EUVD
EUVD-2026-63812

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
wpforms wpforms_pro to 2.0.0.2 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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Executive Summary

This is a Stored Cross-Site Scripting (XSS) vulnerability in the WPForms Pro WordPress plugin affecting versions up to 2.0.0.2. It allows unauthenticated attackers to inject malicious scripts via Single Line Text and Paragraph Text Field Values due to insufficient input sanitization and output escaping. The exploit abuses a widened allowlist for iframe elements with a data-src attribute, enabling javascript: URIs to bypass security and execute when users access infected pages.

Detection Guidance

This vulnerability is specific to the WPForms Pro plugin in WordPress. Detection involves checking the installed version of the plugin and inspecting for malicious scripts in form fields. Use WordPress admin to verify the plugin version and review form entries for unusual iframe or script tags. No direct network/system commands are provided in the context.

Impact Analysis

An attacker could steal sensitive user data, hijack user sessions, or perform actions on behalf of users without their consent. It may also lead to defacement of the website, installation of malware, or redirection to malicious sites. The impact depends on the website's functionality and the attacker's goals.

Compliance Impact

This vulnerability could lead to unauthorized access or data breaches, violating GDPR's data protection requirements and potentially HIPAA's safeguards for protected health information. Organizations may face fines, legal penalties, and reputational damage if exploited.

Mitigation Strategies

Update the WPForms Pro plugin to version 2.0.0.2 or later, which addresses the XSS vulnerability. Remove any suspicious Single Line Text or Paragraph Text Field Values containing iframe elements with data-src attributes. Review pages for unauthorized scripts and restrict user input to trusted sources.

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