CVE-2026-6571: KodExplorer Authorization Bypass Flaw

CVE-2026-6571 Overview

A significant authorization bypass vulnerability has been identified in kodcloud KodExplorer, a popular web-based file management solution. This vulnerability affects the roleGroupAction function within the file /app/controller/systemRole.class.php, where improper authorization controls allow attackers to bypass security restrictions through manipulation of the group_role argument.

The vulnerability stems from improper authorization handling (CWE-285), which occurs when the application fails to perform adequate access control checks before processing user-supplied input to role-related functions. This weakness enables remote attackers to potentially escalate privileges or access restricted functionality without proper authentication.

Critical Impact

Remote attackers can bypass authorization controls in KodExplorer by manipulating the group_role parameter, potentially gaining unauthorized access to system role management functions. The exploit has been publicly disclosed.

Affected Products

• kodcloud KodExplorer up to version 4.52

Discovery Timeline

• 2026-04-19 - CVE-2026-6571 published to NVD
• 2026-04-22 - Last updated in NVD database

Technical Details for CVE-2026-6571

Vulnerability Analysis

This authorization bypass vulnerability occurs in the role management functionality of KodExplorer. The roleGroupAction function in /app/controller/systemRole.class.php processes the group_role argument without implementing proper authorization validation. This creates a condition where authenticated users with lower privileges may be able to manipulate role assignments or access role management capabilities that should be restricted to administrators.

The vulnerability enables network-based attacks, meaning an attacker does not need local access to the target system. Instead, they can exploit this weakness remotely through HTTP requests to the vulnerable endpoint. The attack requires low privileges, indicating that some level of authentication is needed before exploitation can occur.

Root Cause

The root cause of this vulnerability is classified as CWE-285 (Improper Authorization). The roleGroupAction function fails to validate whether the requesting user has sufficient privileges to perform role group operations before processing the group_role parameter. This improper authorization check allows users to access or modify role configurations beyond their authorized scope.

Attack Vector

The attack is executed remotely over the network by sending crafted HTTP requests to the KodExplorer application. An attacker with basic authentication credentials can manipulate the group_role parameter in requests to the systemRole.class.php controller. By supplying specifically crafted values for this parameter, the attacker can bypass the intended authorization controls and perform unauthorized role management operations.

The exploit has been made publicly available, increasing the risk of widespread exploitation. The vendor (kodcloud) was contacted regarding this disclosure but did not respond, leaving users without an official patch.

Detection Methods for CVE-2026-6571

Indicators of Compromise

• Unusual HTTP requests targeting /app/controller/systemRole.class.php with manipulated group_role parameters
• Unexpected changes to user roles or group assignments in KodExplorer
• Authentication logs showing role modifications by unauthorized user accounts
• Anomalous access patterns to administrative role management endpoints

Detection Strategies

• Implement web application firewall (WAF) rules to monitor and filter requests containing suspicious group_role parameter values
• Enable detailed logging for the systemRole.class.php controller and monitor for unauthorized access attempts
• Deploy SentinelOne Singularity XDR to detect behavioral anomalies associated with privilege escalation attempts
• Review access logs for repeated or automated requests to role management endpoints from unexpected sources

Monitoring Recommendations

• Configure alerts for any modifications to system roles outside of scheduled administrative windows
• Monitor network traffic for requests to /app/controller/systemRole.class.php from untrusted IP addresses
• Implement file integrity monitoring on KodExplorer configuration and controller files
• Regularly audit user role assignments to identify unauthorized privilege changes

How to Mitigate CVE-2026-6571

Immediate Actions Required

• Restrict network access to KodExplorer administrative interfaces using firewall rules or network segmentation
• Implement additional authentication layers (such as IP whitelisting) for role management functions
• Review and audit all current user role assignments for unauthorized modifications
• Consider temporarily disabling role management functionality until a patch is available

Patch Information

No official patch has been released by kodcloud at this time. The vendor was contacted regarding this vulnerability disclosure but did not respond. Users should monitor the VulDB vulnerability entry and official kodcloud channels for updates on security patches.

In the absence of a vendor-provided fix, organizations should prioritize implementing compensating controls and consider alternative file management solutions if the risk is unacceptable.

Workarounds

• Deploy a web application firewall (WAF) with custom rules to filter malicious group_role parameter values
• Restrict access to the systemRole.class.php endpoint at the web server level using .htaccess or nginx configuration
• Implement network-level access controls to limit who can reach KodExplorer administrative functions
• Consider deploying KodExplorer behind a reverse proxy with additional authentication requirements

# Example nginx configuration to restrict access to vulnerable endpoint
location ~* /app/controller/systemRole\.class\.php {
    allow 10.0.0.0/8;      # Allow internal network only
    allow 192.168.0.0/16;  # Allow private network
    deny all;              # Deny all other access
    
    # Additional basic auth layer
    auth_basic "Restricted Access";
    auth_basic_user_file /etc/nginx/.htpasswd;
}