CVE-2026-30462: FuelCMS Path Traversal Vulnerability

CVE-2026-30462 Overview

A path traversal vulnerability has been identified in the Blocks module of Daylight Studio FuelCMS v1.5.2. This security flaw allows authenticated attackers to execute directory traversal attacks, potentially enabling unauthorized access to sensitive files outside the intended directory structure. The vulnerability exists due to improper input validation in the Blocks controller, which fails to adequately sanitize user-supplied path parameters.

Critical Impact

Authenticated attackers can leverage this path traversal vulnerability to read sensitive files from the server, potentially exposing configuration files, credentials, or other sensitive data stored outside the web root.

Affected Products

• Daylight Studio FuelCMS v1.5.2
• FuelCMS Blocks Module

Discovery Timeline

• 2026-04-27 - CVE CVE-2026-30462 published to NVD
• 2026-04-27 - Last updated in NVD database

Technical Details for CVE-2026-30462

Vulnerability Analysis

This path traversal vulnerability (CWE-22) resides in the Blocks module of FuelCMS, specifically within the Blocks.php controller. The vulnerability occurs when user-controlled input containing path traversal sequences (such as ../) is not properly sanitized before being used to construct file paths. When exploited, this allows an authenticated attacker to navigate outside the intended directory and access arbitrary files on the server.

The attack requires network access and low-privilege authentication to execute. While the vulnerability does not directly allow code execution, the ability to read sensitive files could lead to further compromise of the system through exposure of credentials, configuration data, or other sensitive information.

Root Cause

The root cause of this vulnerability is improper input validation in the FuelCMS Blocks module. The Blocks.php controller fails to properly sanitize path-related user input, allowing directory traversal sequences to bypass intended access restrictions. This represents a classic CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) vulnerability pattern where user-supplied data is used to construct filesystem paths without adequate validation.

Attack Vector

This vulnerability is exploitable over the network by authenticated users. An attacker with valid low-privilege credentials can craft malicious requests containing directory traversal sequences targeting the Blocks module endpoints. The attack does not require user interaction and can be executed directly against the vulnerable application endpoint.

The attacker manipulates file path parameters by injecting traversal sequences like ../ to escape the intended directory and access files elsewhere on the filesystem. This could enable reading of sensitive configuration files such as database credentials, application secrets, or system files accessible to the web server process.

Detection Methods for CVE-2026-30462

Indicators of Compromise

• Web server access logs containing requests to the Blocks module with path traversal sequences (../, ..%2f, %2e%2e/)
• Unusual file access patterns in application logs indicating attempts to read files outside the FuelCMS installation directory
• HTTP requests targeting fuel/modules/fuel/controllers/Blocks.php with suspicious path parameters

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing directory traversal patterns
• Monitor application logs for requests to the Blocks controller containing encoded or decoded traversal sequences
• Deploy file integrity monitoring to detect unauthorized access to sensitive configuration files
• Review authentication logs for accounts making repeated requests to the Blocks module

Monitoring Recommendations

• Configure alerting for any requests containing ../ patterns targeting FuelCMS endpoints
• Implement anomaly detection for file access operations outside normal application directories
• Enable verbose logging on the FuelCMS application to capture detailed request parameters
• Monitor for access attempts to common sensitive files like /etc/passwd, .htaccess, or configuration files

How to Mitigate CVE-2026-30462

Immediate Actions Required

• Restrict access to the FuelCMS administrative interface to trusted IP addresses only
• Review and audit user accounts with access to the Blocks module
• Implement additional input validation at the web server or WAF level to block traversal sequences
• Monitor application logs for exploitation attempts while awaiting a patch

Patch Information

As of the last NVD update on 2026-04-27, users should monitor the official FuelCMS channels for security updates. Refer to the GitHub FUEL-CMS repository and FuelCMS official documentation for the latest security advisories and patch availability. The Pentest Tools vulnerability report provides additional technical details about the vulnerability.

Workarounds

• Implement strict input validation to reject any path parameters containing .., %2e, or other encoded traversal sequences
• Apply web server configuration to restrict file access to the application's intended directories
• Use a web application firewall (WAF) with path traversal detection rules enabled
• Consider disabling the Blocks module if it is not required for your implementation

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

# Restrict access to sensitive directories
<DirectoryMatch "^/.*/fuel/(application|modules)/">
    Deny from all
</DirectoryMatch>