CVE-2026-25525: OpenMage Magento Path Traversal Flaw

CVE-2026-25525 Overview

CVE-2026-25525 is a path traversal vulnerability affecting OpenMage Magento Long Term Support (LTS), an unofficial, community-driven e-commerce platform that provides an alternative to Magento Community Edition with a high level of backward compatibility. The vulnerability exists in the Dataflow module, which uses a weak blacklist filter to prevent path traversal attacks. This filter can be easily bypassed, allowing an authenticated administrator to read arbitrary files from the server filesystem.

Critical Impact

Authenticated administrators can exploit a weak path traversal filter in the Dataflow module to read sensitive server files, potentially exposing configuration data, credentials, and other confidential information.

Affected Products

• OpenMage Magento LTS versions prior to 20.17.0
• OpenMage Magento (cpe:2.3:a:openmage:magento:*:*:*:*:lts:*:*:*)

Discovery Timeline

• 2026-04-20 - CVE-2026-25525 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2026-25525

Vulnerability Analysis

This path traversal vulnerability (CWE-22) stems from inadequate input sanitization in the Dataflow module of OpenMage Magento LTS. The module implements a blacklist-based filtering approach using PHP's str_replace() function to remove path traversal sequences. However, this single-pass replacement strategy is fundamentally flawed and can be trivially bypassed.

The vulnerability requires authentication with administrator privileges but provides no additional barriers once that access is obtained. Successful exploitation grants read access to arbitrary files on the server filesystem, which could include database credentials, API keys, encryption secrets, and other sensitive configuration data stored outside the web root.

Root Cause

The root cause is the use of a weak blacklist filter that performs a non-recursive string replacement. The code uses str_replace('../', '', $input) to sanitize user input, attempting to remove parent directory traversal sequences. This approach fails because the replacement is performed only once, allowing attackers to craft input strings that result in valid path traversal sequences after the filter processes them.

Attack Vector

An authenticated administrator can exploit this vulnerability by submitting specially crafted file paths through the Dataflow module interface. By using nested traversal patterns such as ..././ or ....//, the attacker can bypass the filter. When the filter processes ..././, it removes the inner ../ sequence, but this leaves behind ../ which the filter does not process again. This allows the attacker to traverse directories and read files outside the intended scope.

For example, if an attacker provides the path ..././..././etc/passwd, the filter will process it as follows:

1. Input: ..././..././etc/passwd
2. After first ../ removal: ../..../etc/passwd → which still contains ../
3. The resulting path allows traversal to /etc/passwd

The attacker can chain multiple bypass patterns to reach any accessible file on the server filesystem.

Detection Methods for CVE-2026-25525

Indicators of Compromise

• Unusual file access patterns in web application logs showing Dataflow module requests with path traversal sequences
• Admin audit logs containing file path parameters with patterns like ..././, ....//, or similar nested traversal attempts
• Error logs indicating attempts to access files outside the Magento installation directory
• Unexpected read operations on sensitive system files such as /etc/passwd, configuration files, or database credentials

Detection Strategies

• Monitor Dataflow module requests for suspicious path patterns containing repeated dots, slashes, or encoded characters
• Implement Web Application Firewall (WAF) rules to detect and block common path traversal bypass patterns
• Enable verbose logging for the Dataflow module and audit all file access operations
• Deploy file integrity monitoring on sensitive configuration files to detect unauthorized access

Monitoring Recommendations

• Configure alerting for any admin panel activity involving the Dataflow import/export functionality
• Review admin user accounts and ensure principle of least privilege is applied
• Implement session monitoring for administrator accounts to detect anomalous behavior
• Set up real-time alerts for file access operations outside expected directories

How to Mitigate CVE-2026-25525

Immediate Actions Required

• Upgrade OpenMage Magento LTS to version 20.17.0 or later immediately
• Review admin account access and remove unnecessary administrator privileges
• Audit recent Dataflow module activity for potential exploitation attempts
• If upgrade is not immediately possible, consider disabling the Dataflow module temporarily

Patch Information

The vulnerability has been patched in OpenMage Magento LTS version 20.17.0. Organizations running affected versions should upgrade as soon as possible. The GitHub Security Advisory GHSA-6vqf-6fhm-7rc6 provides additional details about the fix and affected versions.

Workarounds

• Disable the Dataflow module if it is not required for business operations until the patch can be applied
• Implement additional access controls to restrict which administrators can use the Dataflow functionality
• Deploy a Web Application Firewall with rules configured to block path traversal patterns including bypass variations
• Restrict file system permissions to limit readable files by the web server process

To disable the Dataflow module, administrators can modify the module configuration or use access control lists to restrict the functionality until the upgrade is completed.