CVE-2026-27075: Belfort Theme PHP File Inclusion Vulnerability

CVE-2026-27075 Overview

CVE-2026-27075 is a Local File Inclusion (LFI) vulnerability affecting the Belfort WordPress theme developed by Mikado-Themes. The vulnerability stems from improper control of filename parameters in PHP include/require statements, allowing attackers to include arbitrary local files from the server. This can lead to unauthorized access to sensitive configuration files, source code disclosure, and potentially remote code execution when combined with other techniques such as log poisoning or file upload vulnerabilities.

Critical Impact

This vulnerability enables unauthenticated attackers to read sensitive files on the server, potentially exposing database credentials, configuration data, and other critical system information. In certain configurations, this could escalate to full remote code execution.

Affected Products

• Mikado-Themes Belfort WordPress Theme version 1.0 and earlier
• WordPress installations using the Belfort theme

Discovery Timeline

• 2026-03-25 - CVE-2026-27075 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2026-27075

Vulnerability Analysis

This vulnerability falls under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program). The Belfort theme fails to properly sanitize user-supplied input before passing it to PHP's include or require functions. When a web application dynamically constructs file paths using untrusted input without adequate validation, attackers can manipulate the path to include unintended files from the local filesystem.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring authentication. However, the attack complexity is considered high, as successful exploitation may depend on specific server configurations and the attacker's ability to craft appropriate payloads to traverse directories and locate sensitive files.

Root Cause

The root cause is insufficient input validation and sanitization of user-controlled parameters that are subsequently used in file inclusion operations. The theme likely accepts a parameter (such as a template name or component identifier) that gets directly concatenated into a file path without proper filtering of directory traversal sequences like ../ or validation against an allowlist of permitted values.

Attack Vector

The attack vector is network-based, allowing remote exploitation without user interaction. An attacker can craft malicious HTTP requests containing path traversal sequences to manipulate the file inclusion logic. Common attack patterns include:

The vulnerability can be exploited by manipulating parameters in HTTP requests to the affected theme. Attackers typically use directory traversal sequences such as ../ to navigate outside the intended directory and access sensitive files like /etc/passwd, wp-config.php, or other configuration files containing database credentials and authentication keys. The specific vulnerable parameter and endpoint details are documented in the Patchstack vulnerability database.

Detection Methods for CVE-2026-27075

Indicators of Compromise

• Web server access logs containing path traversal sequences (../, ..%2f, ..%252f) in requests to theme endpoints
• Requests attempting to access sensitive files like wp-config.php, /etc/passwd, or .htaccess through theme parameters
• Unusual file access patterns in PHP error logs indicating failed include attempts
• Evidence of log poisoning attempts combined with LFI exploitation

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block path traversal patterns in HTTP requests
• Implement file integrity monitoring on WordPress core files and sensitive configuration files
• Configure logging to capture all requests to WordPress theme files and endpoints
• Use intrusion detection systems with signatures for common LFI attack patterns

Monitoring Recommendations

• Monitor web server logs for requests containing encoded directory traversal sequences targeting the Belfort theme
• Set up alerts for access attempts to sensitive system files through web requests
• Track failed file inclusion attempts in PHP error logs
• Review Apache/Nginx access logs for unusual patterns targeting theme-related endpoints

How to Mitigate CVE-2026-27075

Immediate Actions Required

• Remove or deactivate the Belfort theme if it is not essential to site operations
• Implement WAF rules to block requests containing path traversal sequences targeting the affected theme
• Review access logs for evidence of exploitation attempts
• Consider switching to an alternative WordPress theme until a patched version is available

Patch Information

As of the last NVD update on 2026-03-26, users should check the Patchstack vulnerability advisory for the latest information on available patches. Contact Mikado-Themes directly for updates regarding a security patch for versions 1.0 and earlier.

Workarounds

• Disable the Belfort theme and switch to a secure alternative theme
• Implement strict WAF rules to filter path traversal patterns in all incoming requests
• Use server-level configuration to restrict PHP file access to specific directories using open_basedir
• Apply WordPress security hardening measures including file permission restrictions

# PHP open_basedir configuration to restrict file access
# Add to php.ini or .htaccess
php_admin_value open_basedir /var/www/html:/tmp

# Apache mod_rewrite rules to block path traversal
RewriteEngine On
RewriteCond %{QUERY_STRING} (\.\./|\.\.%2f|\.\.%252f) [NC]
RewriteRule .* - [F,L]