CVE-2026-25510: CI4MS CodeIgniter CMS RCE Vulnerability

CVE-2026-25510 Overview

CVE-2026-25510 is a critical Remote Code Execution (RCE) vulnerability affecting CI4MS, a CodeIgniter 4-based Content Management System skeleton that provides production-ready modular architecture with RBAC authorization and theme support. Prior to version 0.28.5.0, an authenticated user with file editor permissions can achieve arbitrary PHP code execution on the server by exploiting the file creation and save endpoints.

This vulnerability allows attackers to upload and execute malicious PHP code, potentially leading to complete server compromise. The vulnerability is classified under CWE-94 (Improper Control of Generation of Code, or 'Code Injection'), indicating a fundamental flaw in how the application handles file operations within the administrative interface.

Critical Impact

Authenticated attackers with file editor permissions can achieve full Remote Code Execution, allowing complete server takeover, data exfiltration, and lateral movement within the network.

Affected Products

• CI4MS versions prior to 0.28.5.0
• CodeIgniter 4-based CMS installations using vulnerable CI4MS skeleton
• Systems with file editor functionality enabled for authenticated users

Discovery Timeline

• 2026-02-03 - CVE-2026-25510 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2026-25510

Vulnerability Analysis

This Remote Code Execution vulnerability exists in the file editor functionality of CI4MS. The application provides authenticated users who have file editor permissions with the ability to create and modify files through dedicated endpoints. However, the implementation fails to properly validate or restrict the types of files that can be created or the content that can be saved.

The vulnerability allows an attacker with file editor permissions to create arbitrary PHP files on the server. Since PHP files are directly executable by the web server, any malicious code injected through this mechanism will be executed in the context of the web server process. This represents a complete compromise of the application's security model, as the attacker can execute arbitrary system commands, access sensitive data, modify application logic, or establish persistent backdoor access.

The scope of this vulnerability extends beyond the vulnerable component itself (Changed scope in CVSS), meaning successful exploitation can affect resources beyond the security scope of the vulnerable component, potentially impacting other applications hosted on the same server.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and file type restrictions within the file creation and save endpoints of the CI4MS file editor module. The application fails to implement proper controls to:

1. Restrict the file extensions that can be created or modified
2. Validate file content to prevent executable code injection
3. Properly sandbox file operations to non-executable directories
4. Implement content-type verification for uploaded or created files

This lack of defense-in-depth allows authenticated attackers to bypass expected usage patterns and weaponize the legitimate file editor functionality for malicious purposes.

Attack Vector

The attack vector is network-based and requires low privileges (authenticated access with file editor permissions). An attacker would exploit this vulnerability through the following general approach:

1. Authenticate to the CI4MS administrative interface with an account that has file editor permissions
2. Navigate to the file editor functionality
3. Use the file creation endpoint to create a new PHP file with malicious content (e.g., a web shell)
4. Access the newly created PHP file through a web browser to execute the malicious code
5. Leverage the code execution to perform further malicious activities such as privilege escalation, data theft, or establishing persistence

The vulnerability requires no user interaction and can be exploited with low attack complexity. For detailed technical analysis, refer to the GitHub Security Advisory GHSA-gp56-f67f-m4px.

Detection Methods for CVE-2026-25510

Indicators of Compromise

• Unexpected PHP files created in web-accessible directories, particularly with generic names or obfuscated content
• Anomalous file creation activity in application logs from users with file editor permissions
• Web shell signatures or base64-encoded PHP code in newly created files
• Unusual outbound network connections from the web server process

Detection Strategies

• Monitor file system changes for new PHP file creation outside of normal deployment patterns
• Implement file integrity monitoring (FIM) on critical web directories to detect unauthorized modifications
• Review application access logs for suspicious activity involving file editor endpoints
• Deploy web application firewall (WAF) rules to detect common web shell patterns and code injection attempts

Monitoring Recommendations

• Enable detailed logging for all file editor operations including file creation, modification, and deletion
• Configure alerts for any PHP file creation by non-administrative deployment processes
• Monitor for execution of newly created PHP files that were not part of legitimate deployments
• Implement behavioral analysis to detect anomalous activity patterns from authenticated users

How to Mitigate CVE-2026-25510

Immediate Actions Required

• Upgrade CI4MS to version 0.28.5.0 or later immediately
• Audit all users with file editor permissions and remove access where not strictly necessary
• Review recently created files in web-accessible directories for signs of compromise
• Consider temporarily disabling file editor functionality until the patch is applied

Patch Information

The vulnerability has been addressed in CI4MS version 0.28.5.0. The fix is available in commit 86be2930d1c54eb7575102563302b2f3bafcb653. Organizations should update to this version or later to remediate the vulnerability. The patch implements proper validation and restrictions on the file editor functionality to prevent arbitrary PHP file creation.

For complete details on the vulnerability and patch, refer to the GitHub Security Advisory.

Workarounds

• Disable the file editor functionality entirely until the patch can be applied
• Restrict file editor permissions to only essential administrative accounts
• Implement web server configuration to prevent execution of PHP files in user-writable directories
• Deploy additional WAF rules to block requests containing PHP code patterns in file editor endpoints

# Example Apache configuration to restrict PHP execution in specific directories
# Add to .htaccess or Apache configuration
<Directory "/path/to/ci4ms/writable">
    php_admin_flag engine off
    <FilesMatch "\.php$">
        Require all denied
    </FilesMatch>
</Directory>