CVE-2026-27383: RadiusTheme Metro Path Traversal Flaw

CVE-2026-27383 Overview

CVE-2026-27383 is an Improper Control of Filename for Include/Require Statement in PHP Program vulnerability (CWE-98) affecting the RadiusTheme Metro WordPress theme. This Local File Inclusion (LFI) vulnerability allows attackers to manipulate file paths within PHP include or require statements, potentially enabling them to read sensitive files or execute arbitrary code on the server.

Critical Impact
Attackers exploiting this vulnerability may gain unauthorized access to sensitive configuration files, credentials, or achieve remote code execution through log poisoning or other LFI-to-RCE techniques.

Affected Products

RadiusTheme Metro WordPress Theme versions through 2.13
WordPress installations running vulnerable Metro theme versions

Discovery Timeline

2026-03-05 - CVE-2026-27383 published to NVD
2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-27383

Vulnerability Analysis

This vulnerability stems from improper validation and sanitization of user-controlled input that is subsequently used in PHP include() or require() statements within the RadiusTheme Metro theme. When user input is directly concatenated or interpolated into file path parameters without proper filtering, attackers can traverse directories and include arbitrary local files from the server's filesystem.

The flaw is classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program), which specifically addresses scenarios where PHP applications fail to restrict the files that can be included through dynamic file path construction. While the vulnerability description mentions "PHP Remote File Inclusion," the actual impact is limited to Local File Inclusion, meaning attackers can only include files already present on the target server.

Root Cause

The root cause lies in insufficient input validation where user-supplied data is passed to PHP file inclusion functions without adequate sanitization. The Metro theme likely accepts a parameter (through GET, POST, or other input vectors) that influences which template or component file is loaded, but fails to properly validate that the requested file is within the expected directory or matches an allowlist of permitted files.

Attack Vector

An attacker can exploit this vulnerability by crafting malicious requests that include directory traversal sequences (such as ../) or absolute file paths. This allows them to break out of the intended theme directory and access sensitive files elsewhere on the server, including:

WordPress configuration files (wp-config.php) containing database credentials
System files like /etc/passwd for user enumeration
Log files that could be poisoned for code execution
Other plugin or theme files containing sensitive information

The exploitation mechanism involves manipulating a vulnerable parameter to include unintended files. For detailed technical analysis and proof-of-concept information, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2026-27383

Indicators of Compromise

Unusual HTTP requests containing directory traversal patterns (../, ..%2f, %2e%2e/) targeting the Metro theme
Requests attempting to access known sensitive files through theme parameters
Web server logs showing attempts to include files outside the theme directory
Error messages revealing file path information or inclusion failures

Detection Strategies

Implement Web Application Firewall (WAF) rules to detect and block LFI attack patterns including null byte injection and directory traversal sequences
Monitor web server access logs for requests containing suspicious path traversal characters targeting /wp-content/themes/metro/
Deploy file integrity monitoring to detect unauthorized access attempts to sensitive configuration files
Utilize SIEM correlation rules to identify patterns of LFI exploitation attempts across multiple endpoints

Monitoring Recommendations

Enable verbose PHP error logging while ensuring errors are not displayed to end users
Configure intrusion detection systems to alert on common LFI payload patterns
Implement centralized log aggregation for WordPress installations to correlate potential attack attempts
Set up alerts for any access attempts to sensitive system files like wp-config.php through non-standard paths

How to Mitigate CVE-2026-27383

Immediate Actions Required

Review the RadiusTheme Metro theme for available security updates and apply patches immediately when released
Implement a Web Application Firewall with rules specifically targeting LFI attack vectors
Audit all instances of PHP include(), require(), and related functions within the theme for proper input validation
Consider disabling or replacing the vulnerable theme until an official patch is available

Patch Information

At the time of publication, users should monitor the Patchstack Vulnerability Report for updates on official patches from RadiusTheme. WordPress administrators should ensure they have automatic update notifications enabled and check the theme vendor's official channels for security advisories.

Workarounds

Implement server-level restrictions using open_basedir PHP directive to limit which directories PHP can access
Add .htaccess rules to block requests containing directory traversal patterns targeting the theme
Use a security plugin such as Wordfence or Sucuri to add additional protection layers against LFI attacks
Temporarily restrict access to the affected theme functionality if the vulnerable code path can be identified

bash

# Apache .htaccess configuration to block common LFI patterns
<IfModule mod_rewrite.c>
    RewriteEngine On
    # Block directory traversal attempts
    RewriteCond %{QUERY_STRING} (\.\./|\.\.) [NC,OR]
    RewriteCond %{QUERY_STRING} (\.%2e|%2e\.|%2e%2e) [NC]
    RewriteRule ^wp-content/themes/metro/.* - [F,L]
</IfModule>

# PHP open_basedir restriction (php.ini or .user.ini)
# open_basedir = /var/www/html/:/tmp/