CVE-2026-2442: WordPress Pagelayer CRLF Injection Flaw

CVE-2026-2442 Overview

The Page Builder: Pagelayer – Drag and Drop website builder plugin for WordPress contains a CRLF Injection vulnerability (CWE-93) in all versions up to and including 2.0.7. This vulnerability exists in the contact form handler, which performs placeholder substitution on attacker-controlled form fields and subsequently passes the resulting values into email headers without properly sanitizing CR/LF (Carriage Return/Line Feed) characters. This allows unauthenticated attackers to inject arbitrary email headers such as Bcc and Cc, effectively abusing the form's email delivery functionality through the email parameter when targeting a contact form configured to use placeholders in mail template headers.

Critical Impact

Unauthenticated attackers can inject arbitrary email headers to hijack email functionality, potentially enabling spam campaigns, phishing attacks, or sensitive information disclosure through manipulated email delivery.

Affected Products

• Page Builder: Pagelayer – Drag and Drop website builder for WordPress versions ≤ 2.0.7

Discovery Timeline

• 2026-03-28 - CVE CVE-2026-2442 published to NVD
• 2026-03-30 - Last updated in NVD database

Technical Details for CVE-2026-2442

Vulnerability Analysis

The vulnerability stems from improper handling of user-supplied input in the Pagelayer plugin's contact form functionality. When the plugin processes contact form submissions, it performs placeholder substitution using values provided by the user. These substituted values are then incorporated directly into email headers without adequate sanitization.

The core issue is the failure to remove or encode CRLF sequences (\r\n or %0d%0a) from user input before constructing email headers. In email protocols (SMTP), headers are separated by CRLF sequences, meaning an attacker who can inject these characters can effectively terminate the current header and introduce new ones.

This vulnerability requires the target contact form to be configured to use placeholders within mail template headers, which is a common configuration pattern for personalized email responses.

Root Cause

The root cause is inadequate input validation and sanitization in the contact form handler. Specifically, the plugin fails to strip or encode CR (Carriage Return - \r or %0d) and LF (Line Feed - \n or %0a) characters from form field values before they are substituted into email headers. This violates the security principle of input sanitization before use in security-sensitive contexts like email header construction.

Attack Vector

The attack can be executed remotely over the network by any unauthenticated user. An attacker identifies a WordPress site using the Pagelayer plugin with a contact form that utilizes placeholder substitution in email headers. The attacker then crafts a malicious form submission containing CRLF sequences followed by additional email headers in the email parameter or other form fields used in header placeholders.

For example, an attacker could inject victim@example.com%0d%0aBcc:attacker@evil.com into the email field, causing the form to send a copy of all form submissions to the attacker's address. This technique can also be used to inject Cc headers, modify reply-to addresses, or add other arbitrary headers to manipulate email routing and content.

Technical details regarding the specific code changes can be found in the WordPress Plugin Changeset.

Detection Methods for CVE-2026-2442

Indicators of Compromise

• Unusual patterns in web server logs showing URL-encoded CRLF sequences (%0d%0a, %0D%0A) in POST request parameters to contact form endpoints
• Email logs showing unexpected Bcc or Cc recipients on emails originating from WordPress contact forms
• Reports of spam or phishing emails originating from your domain's WordPress contact forms
• Increased email sending volume from WordPress-associated mail accounts

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block CRLF sequences in form submissions, particularly in email-related fields
• Enable detailed logging for the WordPress mail system to monitor for anomalous header injection patterns
• Deploy SentinelOne Singularity to monitor for suspicious web application behavior and potential exploitation attempts

Monitoring Recommendations

• Review email server logs for unusual header patterns or unexpected recipient additions
• Monitor WordPress plugin versions and ensure timely updates to patched versions
• Implement alerting on contact form submission anomalies, particularly those containing encoded special characters

How to Mitigate CVE-2026-2442

Immediate Actions Required

• Update the Pagelayer plugin to a version newer than 2.0.7 immediately
• Audit contact forms for configurations using placeholders in email headers and consider removing header-based placeholders until patching is complete
• Implement server-side input validation to strip CRLF sequences from all user-supplied form data

Patch Information

The vulnerability has been addressed by the plugin developers. The fix can be reviewed in the WordPress Plugin Changeset. Update the Pagelayer plugin through the WordPress admin dashboard or manually download the patched version from the WordPress plugin repository. For detailed vulnerability information, refer to the Wordfence Vulnerability Report.

Workarounds

• Temporarily disable contact forms that use placeholder substitution in email headers until the plugin is updated
• Implement server-level input filtering using .htaccess rules or web server configurations to block requests containing CRLF sequences
• Use a Web Application Firewall (WAF) to filter malicious input patterns before they reach the WordPress application

# Example Apache .htaccess rule to block CRLF injection attempts
RewriteEngine On
RewriteCond %{QUERY_STRING} (%0d|%0a|%0D|%0A) [NC,OR]
RewriteCond %{REQUEST_BODY} (%0d|%0a|%0D|%0A) [NC]
RewriteRule .* - [F,L]