CVE-2026-28089: Daiquiri Theme File Inclusion Vulnerability

CVE-2026-28089 Overview

CVE-2026-28089 is a Local File Inclusion (LFI) vulnerability affecting the ThemeREX Daiquiri WordPress theme. The vulnerability stems from improper control of filename parameters used in PHP include/require statements, allowing attackers to include arbitrary local files from the server. This can lead to sensitive information disclosure, potential code execution if combined with other techniques, and complete compromise of the WordPress installation.

Critical Impact

Unauthenticated attackers can exploit this LFI vulnerability to read sensitive configuration files, access WordPress credentials, and potentially achieve remote code execution through log poisoning or other chaining techniques.

Affected Products

• ThemeREX Daiquiri WordPress Theme versions up to and including 1.2.4
• WordPress installations running vulnerable Daiquiri theme versions
• Web servers hosting affected WordPress sites

Discovery Timeline

• 2026-03-05 - CVE-2026-28089 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-28089

Vulnerability Analysis

This vulnerability is classified as CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program). The Daiquiri WordPress theme fails to properly sanitize user-supplied input before passing it to PHP's include(), require(), include_once(), or require_once() functions. This allows attackers to manipulate the file path and include arbitrary files from the local file system.

The network-accessible attack vector means exploitation can be performed remotely without authentication. While the attack complexity is high, successful exploitation can result in complete compromise of confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause lies in insufficient input validation and sanitization of user-controlled parameters that influence file inclusion paths. The theme accepts user input that directly or indirectly controls which files are included by PHP, without implementing proper path traversal protections or allowlist-based file validation.

Common vulnerable patterns include:

• Direct use of $_GET or $_POST parameters in include statements
• Insufficient filtering of path traversal sequences like ../
• Missing validation against an allowlist of permitted files
• Failure to restrict file inclusion to intended directories

Attack Vector

The vulnerability can be exploited over the network by sending crafted HTTP requests to the vulnerable WordPress installation. Attackers can leverage path traversal techniques to escape the intended directory and access sensitive files such as:

• /etc/passwd for user enumeration
• wp-config.php for database credentials
• Log files for potential log poisoning attacks
• Other PHP files for code execution

The vulnerability mechanism involves manipulating URL parameters or POST data to inject path traversal sequences (e.g., ../../../etc/passwd) into file inclusion operations. See the Patchstack WordPress Vulnerability Report for additional technical details.

Detection Methods for CVE-2026-28089

Indicators of Compromise

• Unusual HTTP requests containing path traversal sequences (../, ..%2f, %2e%2e/) targeting theme endpoints
• Web server logs showing attempts to access sensitive system files through theme parameters
• Unexpected file access patterns in PHP error logs indicating attempted local file inclusion
• Evidence of wp-config.php or system configuration file reads in access logs

Detection Strategies

• Configure web application firewalls (WAF) to detect and block path traversal patterns in HTTP requests
• Implement file integrity monitoring on sensitive configuration files
• Deploy runtime application self-protection (RASP) solutions to detect file inclusion attacks
• Enable detailed logging for theme-related HTTP endpoints and monitor for anomalies

Monitoring Recommendations

• Monitor web server access logs for requests containing encoded or plain path traversal sequences
• Set up alerts for HTTP requests with unusual file extensions or paths targeting the Daiquiri theme directory
• Review PHP error logs for failed file inclusion attempts that may indicate reconnaissance activity
• Implement intrusion detection rules for LFI attack patterns specific to WordPress themes

How to Mitigate CVE-2026-28089

Immediate Actions Required

• Deactivate and remove the Daiquiri theme from production WordPress installations immediately
• Switch to an alternative secure WordPress theme until a patched version is available
• Review web server logs for evidence of prior exploitation attempts
• Implement WAF rules to block path traversal attacks as a temporary mitigation

Patch Information

At the time of publication, no official patch has been released by ThemeREX for this vulnerability. Site administrators should monitor the Patchstack WordPress Vulnerability Report for updates on remediation options and contact ThemeREX directly for patch availability.

Until an official patch is available, the theme should be removed from production environments or protected with compensating controls.

Workarounds

• Implement strict WAF rules to block requests containing path traversal sequences to WordPress theme directories
• Configure PHP open_basedir directive to restrict file access to the WordPress installation directory
• Disable direct access to theme files through .htaccess rules where possible
• Use server-level file permissions to restrict PHP's ability to read sensitive configuration files

# Example .htaccess rule to block path traversal attempts
RewriteEngine On
RewriteCond %{QUERY_STRING} (\.\./|\.\.%2f|%2e%2e/) [NC,OR]
RewriteCond %{REQUEST_URI} (\.\./|\.\.%2f|%2e%2e/) [NC]
RewriteRule .* - [F,L]

# PHP open_basedir configuration in php.ini or .htaccess
# Restrict PHP file access to WordPress directory only
php_admin_value open_basedir /var/www/html/wordpress/:/tmp/