CVE-2026-7398: BioinfoMCP Path Traversal Vulnerability

CVE-2026-7398 Overview

A path traversal vulnerability has been identified in florensiawidjaja BioinfoMCP, a bioinformatics platform. This vulnerability affects the Upload function within the file bioinfo_mcp_platform/app.py at the Upload Endpoint component. By manipulating the Name argument, an attacker can perform path traversal attacks. The vulnerability can be exploited remotely without authentication, allowing attackers to potentially read or write files outside of the intended directory structure.

Critical Impact
Remote attackers can exploit this path traversal vulnerability to access or manipulate files outside the intended upload directory, potentially leading to unauthorized data access, configuration file exposure, or arbitrary file overwrites on the target system.

Affected Products

BioinfoMCP (up to commit 7ada7918b9e515604d3c0ae264d3a9af10bf6e54)
bioinfo_mcp_platform/app.py - Upload Endpoint component

Discovery Timeline

2026-04-29 - CVE CVE-2026-7398 published to NVD
2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-7398

Vulnerability Analysis

This path traversal vulnerability (CWE-22) resides in the Upload Endpoint of the BioinfoMCP platform. The vulnerability stems from insufficient input validation in the Upload function located in bioinfo_mcp_platform/app.py. When processing file uploads, the application fails to properly sanitize the Name argument, allowing attackers to include directory traversal sequences (such as ../) in the filename parameter.

Path traversal vulnerabilities occur when an application uses user-supplied input to construct file paths without adequately validating or sanitizing the input. In this case, an attacker can craft malicious requests to the Upload Endpoint that include path traversal characters, enabling them to write files to arbitrary locations on the server filesystem.

The project uses continuous delivery with rolling releases, which means no specific version numbers are assigned to affected or patched releases. The vulnerability was reported to the project maintainers through a GitHub Issue, but no response has been received at the time of disclosure.

Root Cause

The root cause of this vulnerability is improper input validation in the file upload handling logic. The Upload function does not adequately sanitize or validate the Name parameter before using it to construct file paths on the server. This allows specially crafted input containing path traversal sequences to escape the intended upload directory.

Proper input sanitization should include:

Stripping or rejecting path separator characters (/, \)
Removing or blocking relative path sequences (.., ./)
Validating that the resolved path remains within the intended upload directory
Using basename functions to extract only the filename portion

Attack Vector

The attack can be initiated remotely via the network. An attacker sends a crafted HTTP request to the Upload Endpoint with a manipulated Name parameter containing path traversal sequences. Since no authentication appears to be required, this attack can be executed by unauthenticated remote attackers.

The vulnerability allows attackers to potentially:

Write malicious files to arbitrary locations on the server
Overwrite critical configuration files
Access sensitive files outside the upload directory
Achieve code execution if combined with other vulnerabilities

The vulnerability mechanism involves manipulating the Name parameter in upload requests to include directory traversal sequences such as ../. When the application processes this input without proper sanitization, it constructs a file path that resolves outside the intended upload directory. For technical details, refer to the GitHub Issue #2 Discussion and VulDB Vulnerability #360122.

Detection Methods for CVE-2026-7398

Indicators of Compromise

HTTP requests to the Upload Endpoint containing path traversal sequences (../, ..\\, %2e%2e%2f) in the Name parameter
Unexpected file creation or modification outside the designated upload directory
Web server access logs showing suspicious upload requests with encoded or literal path traversal characters
Unusual file access patterns in system audit logs indicating reads or writes to sensitive directories

Detection Strategies

Implement web application firewall (WAF) rules to detect and block requests containing path traversal patterns in upload parameters
Monitor HTTP request logs for patterns indicative of path traversal attempts (multiple ../ sequences, URL-encoded variants)
Deploy file integrity monitoring (FIM) on critical system directories to detect unauthorized file modifications
Configure intrusion detection systems (IDS) with signatures for path traversal attack patterns

Monitoring Recommendations

Enable detailed logging on the BioinfoMCP application to capture all upload requests and their parameters
Implement real-time alerting for any file operations occurring outside designated upload directories
Review web server access logs regularly for suspicious patterns targeting the Upload Endpoint
Deploy endpoint detection and response (EDR) solutions to monitor for anomalous file system activity

How to Mitigate CVE-2026-7398

Immediate Actions Required

Restrict network access to the BioinfoMCP Upload Endpoint to trusted IP addresses only
Implement a web application firewall (WAF) with rules to block path traversal patterns
Disable the Upload Endpoint if it is not critical to operations until a patch is available
Review server file systems for any unauthorized files that may indicate prior exploitation

Patch Information

No official patch has been released by the project maintainers. The project uses continuous delivery with rolling releases, and the maintainers have not yet responded to the vulnerability report submitted via GitHub Issue #2. Organizations using BioinfoMCP should monitor the GitHub Repository for updates and consider implementing the workarounds below.

Workarounds

Implement input validation at the application or reverse proxy level to reject upload requests containing path traversal sequences
Use a reverse proxy configuration to sanitize incoming requests before they reach the application
Restrict file system permissions for the application user to limit the impact of successful exploitation
Consider containerizing the application to limit file system access scope

bash

# Example nginx configuration to block path traversal attempts
location /upload {
    # Block requests with path traversal sequences
    if ($request_uri ~* "\.\.") {
        return 403;
    }
    
    # Additional security headers
    add_header X-Content-Type-Options nosniff;
    add_header X-Frame-Options DENY;
    
    proxy_pass http://bioinformcp_backend;
}