CVE-2026-7319: Elinsky Execution-System-MCP Path Traversal

CVE-2026-7319 Overview

A path traversal vulnerability has been discovered in elinsky execution-system-mcp version 0.1.0. The vulnerability exists in the function _get_context_file_path within the file src/execution_system_mcp/server.py, which is part of the add_action Tool component. An attacker can manipulate the context argument to traverse directories and potentially access or modify files outside of the intended directory structure. The attack can be initiated remotely over the network, and an exploit has been publicly disclosed.

Critical Impact

Remote attackers can exploit this path traversal flaw to read or write arbitrary files on the affected system by manipulating the context parameter, potentially leading to information disclosure, data tampering, or further system compromise.

Affected Products

• elinsky execution-system-mcp 0.1.0

Discovery Timeline

• 2026-04-28 - CVE CVE-2026-7319 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-7319

Vulnerability Analysis

This vulnerability is classified as CWE-22 (Path Traversal), a flaw that occurs when user-controllable input is used to construct file paths without proper validation or sanitization. In the case of execution-system-mcp, the _get_context_file_path function in server.py fails to adequately sanitize the context argument before using it to build file paths.

The add_action Tool component accepts user input that is passed to this function, allowing attackers to inject path traversal sequences such as ../ to escape the intended directory and access files elsewhere on the filesystem. Since this can be exploited remotely over the network without authentication, attackers could potentially read sensitive configuration files, access credentials, or overwrite critical system files depending on the application's permissions.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the _get_context_file_path function. The function constructs file paths using the user-supplied context parameter without properly sanitizing or validating the input for path traversal sequences. This allows malicious input containing directory traversal characters (e.g., ../ or ..\\) to break out of the intended directory structure.

Attack Vector

The attack vector is network-based, requiring no authentication or user interaction. An attacker can send specially crafted requests to the add_action Tool endpoint with a malicious context parameter containing path traversal sequences. The vulnerable function then processes this input, allowing the attacker to access files outside the intended directory.

For example, by supplying a context value like ../../../etc/passwd, an attacker could potentially read sensitive system files. The exploit methodology involves manipulating the context argument to traverse the directory structure and access or manipulate files that should be restricted.

Technical details and proof-of-concept information are available at the GitHub Issue Tracker and VulDB entry.

Detection Methods for CVE-2026-7319

Indicators of Compromise

• HTTP requests containing path traversal sequences (../, ..%2f, ..\\, ..%5c) in the context parameter of add_action Tool requests
• Unusual file access patterns in application logs, particularly attempts to access files outside expected directories
• Unexpected file read or write operations in directories not normally accessed by the execution-system-mcp application

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing path traversal patterns in URL parameters and request bodies
• Monitor application logs for context parameters containing suspicious path sequences or references to sensitive system files
• Deploy file integrity monitoring on critical system directories to detect unauthorized access attempts

Monitoring Recommendations

• Enable verbose logging for the execution-system-mcp application to capture all incoming requests and context parameter values
• Configure alerting for any file access attempts outside the application's designated context directory
• Review server access logs regularly for patterns indicating reconnaissance or exploitation attempts

How to Mitigate CVE-2026-7319

Immediate Actions Required

• Upgrade elinsky execution-system-mcp to a patched version when available
• Implement input validation to reject context parameters containing path traversal sequences (../, ..\\, encoded variants)
• Apply least privilege principles to the application's filesystem permissions to limit the impact of successful exploitation
• Consider deploying a WAF with path traversal detection rules as an additional layer of defense

Patch Information

Users should monitor the official GitHub repository for security updates and patches. The vulnerability was reported via the GitHub Issue Tracker. Until an official patch is released, implement the workarounds described below to reduce exposure.

Workarounds

• Implement strict input validation on the context parameter to reject any input containing .., /, or \ characters
• Use allowlisting to only permit expected context values rather than blocklisting malicious patterns
• Apply path canonicalization and verify the resolved path is within the expected base directory before processing

# Example: Validate that resolved path stays within allowed directory
# In Python, use os.path.realpath() and verify prefix
ALLOWED_BASE="/var/app/contexts"
# Ensure resolved_path.startswith(ALLOWED_BASE) before accessing files