CVE-2026-22405: Overton Theme File Inclusion Vulnerability

CVE-2026-22405 Overview

CVE-2026-22405 is a PHP Local File Inclusion (LFI) vulnerability affecting the Overton WordPress theme developed by Mikado-Themes. The vulnerability stems from improper control of filename parameters used in PHP include/require statements, allowing attackers to include arbitrary local files on the server. This can lead to sensitive information disclosure, configuration file exposure, and potentially remote code execution when combined with other attack techniques.

Critical Impact

Attackers can exploit this LFI vulnerability to read sensitive files from the WordPress installation, including configuration files containing database credentials, and potentially achieve code execution through log poisoning or other file inclusion chains.

Affected Products

• Mikado-Themes Overton WordPress Theme version 1.3 and earlier
• WordPress installations using vulnerable Overton theme versions

Discovery Timeline

• 2026-03-05 - CVE CVE-2026-22405 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-22405

Vulnerability Analysis

This vulnerability is classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program). The Overton WordPress theme fails to properly sanitize user-controlled input before using it in PHP file inclusion functions such as include(), include_once(), require(), or require_once().

When user input is passed directly to these functions without adequate validation, an attacker can manipulate the file path to include arbitrary files from the local filesystem. This type of vulnerability is particularly dangerous in WordPress environments where predictable file structures and sensitive configuration files like wp-config.php are present.

Root Cause

The root cause of this vulnerability is insufficient input validation and sanitization of user-supplied parameters that are subsequently used in PHP file inclusion operations. The Overton theme likely accepts a parameter (potentially for template selection or component loading) that is not properly filtered for path traversal sequences or validated against an allowlist of permitted files.

Common vulnerable patterns include:

• Direct use of $_GET or $_POST parameters in include statements
• Insufficient filtering of path traversal sequences like ../
• Missing validation against a predefined list of allowed files
• Improper handling of null bytes or URL encoding in older PHP versions

Attack Vector

The attack vector for this LFI vulnerability involves manipulating HTTP request parameters to traverse directories and include sensitive files. Attackers typically craft malicious requests containing path traversal sequences to escape the intended directory context and access files elsewhere on the filesystem.

In WordPress environments, common targets include:

• wp-config.php - Contains database credentials and authentication keys
• /etc/passwd - User enumeration on Linux systems
• Log files - For potential log poisoning attacks leading to RCE
• Other plugin/theme configuration files containing sensitive data

For detailed technical information about this vulnerability, refer to the Patchstack WordPress Vulnerability Database.

Detection Methods for CVE-2026-22405

Indicators of Compromise

• Unusual HTTP requests containing path traversal sequences (../, ..%2f, ..%252f) in theme-related parameters
• Access logs showing requests attempting to include system files like /etc/passwd or wp-config.php
• Error logs indicating failed file inclusion attempts or permission denied errors for files outside the web root
• Unexpected access patterns to the Overton theme endpoints

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block path traversal patterns in request parameters
• Monitor access logs for requests containing encoded or double-encoded traversal sequences
• Deploy file integrity monitoring on sensitive WordPress configuration files
• Configure intrusion detection systems to alert on LFI attack signatures

Monitoring Recommendations

• Enable verbose logging for PHP errors and monitor for inclusion-related warnings
• Set up alerting for anomalous requests to WordPress theme files
• Monitor for unusual file access patterns on the web server
• Implement centralized log aggregation to correlate potential exploitation attempts across multiple indicators

How to Mitigate CVE-2026-22405

Immediate Actions Required

• Update the Overton WordPress theme to the latest patched version as soon as one becomes available
• If no patch is available, consider temporarily disabling or replacing the Overton theme
• Implement WAF rules to block path traversal attempts targeting the vulnerable theme
• Review access logs for any evidence of prior exploitation attempts

Patch Information

Organizations should monitor the Patchstack advisory and Mikado-Themes official channels for security updates. Until a patch is released, implement the workarounds described below to reduce exposure to this vulnerability.

Workarounds

• Implement strict input validation using a Web Application Firewall to block path traversal sequences
• Use WordPress security plugins that provide virtual patching capabilities for known vulnerabilities
• Restrict file system permissions to limit readable files from the web server process
• Consider switching to an alternative WordPress theme until a security patch is available

# Apache .htaccess rule to block common LFI patterns
# Add to WordPress root .htaccess file
RewriteEngine On
RewriteCond %{QUERY_STRING} (\.\./|\.\.%2f|\.\.%252f) [NC,OR]
RewriteCond %{QUERY_STRING} (etc/passwd|wp-config\.php) [NC]
RewriteRule .* - [F,L]