CVE-2026-7066: Simple OpenStack MCP RCE Vulnerability

CVE-2026-7066 Overview

A command injection vulnerability has been identified in the choieastsea simple-openstack-mcp project, affecting the exec_openstack function within the server.py file. This vulnerability allows remote attackers to execute arbitrary operating system commands through improper input handling, potentially leading to complete system compromise.

Critical Impact

Remote attackers can exploit this OS command injection vulnerability to execute arbitrary commands on the underlying system without authentication, potentially leading to data theft, lateral movement, or complete infrastructure compromise.

Affected Products

• simple-openstack-mcp up to commit 767b2f4a8154cca344344b9725537a58399e6036
• All versions prior to a security patch (rolling release model - no specific version numbers)

Discovery Timeline

• 2026-04-27 - CVE-2026-7066 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-7066

Vulnerability Analysis

This vulnerability is classified as CWE-77 (Improper Neutralization of Special Elements used in a Command), commonly known as OS Command Injection. The vulnerable component resides in the exec_openstack function within server.py, which fails to properly sanitize user-controlled input before passing it to system command execution functions.

The project follows a rolling release model, meaning continuous delivery without traditional version numbers. This makes tracking vulnerable deployments more challenging, as organizations must verify their deployment against the specific commit hash rather than a version number.

The vulnerability has been publicly disclosed through a GitHub Issue, and exploit information is available, increasing the risk of active exploitation. The project maintainer was notified but has not yet responded to the security disclosure.

Root Cause

The root cause of this vulnerability lies in the exec_openstack function's failure to implement proper input validation and sanitization. When user-supplied data is concatenated directly into OS command strings without escaping or validation, attackers can inject malicious command sequences using shell metacharacters such as semicolons (;), pipes (|), or command substitution operators ($()).

This is a classic command injection pattern where the application trusts external input and passes it directly to system shell execution without proper sanitization or the use of parameterized command execution methods.

Attack Vector

The attack vector is network-based, allowing remote exploitation without requiring authentication or user interaction. An attacker can craft malicious input containing shell metacharacters that, when processed by the vulnerable exec_openstack function, break out of the intended command context and execute arbitrary commands.

The exploitation flow typically involves:

1. Identifying input fields that reach the vulnerable function
2. Crafting payloads containing shell metacharacters and malicious commands
3. Sending the crafted input via network requests to the vulnerable endpoint
4. Achieving arbitrary command execution on the target system

For technical details on the exploitation mechanism, refer to the VulDB vulnerability details and the GitHub issue discussion.

Detection Methods for CVE-2026-7066

Indicators of Compromise

• Unusual process spawning from the Python application process, particularly shell interpreters like /bin/sh or /bin/bash
• Unexpected network connections initiated from the server running simple-openstack-mcp
• Suspicious command-line arguments in process logs containing shell metacharacters or encoded payloads
• Anomalous file system modifications or creation of unauthorized files in web-accessible directories

Detection Strategies

• Implement application-level logging to capture all inputs processed by the exec_openstack function and analyze for injection patterns
• Deploy Web Application Firewalls (WAF) with rules to detect command injection patterns in HTTP request parameters
• Configure Security Information and Event Management (SIEM) to alert on process execution anomalies from the application context
• Utilize endpoint detection solutions to monitor for suspicious child process creation from the Python server process

Monitoring Recommendations

• Enable verbose logging for all OpenStack-related command executions and review logs regularly for anomalies
• Monitor system call activity using auditd or similar tools to track command execution from the application
• Implement network segmentation monitoring to detect unauthorized outbound connections from the application server
• Set up file integrity monitoring on critical system directories to detect post-exploitation activities

How to Mitigate CVE-2026-7066

Immediate Actions Required

• Audit your deployment to verify the commit hash in use against the vulnerable commit 767b2f4a8154cca344344b9725537a58399e6036
• Implement network-level access controls to restrict access to the simple-openstack-mcp service to trusted sources only
• Deploy a Web Application Firewall with command injection detection rules as a compensating control
• Consider temporarily disabling the affected functionality if it is not critical to operations until a patch is available

Patch Information

As of the last NVD update on 2026-04-29, no official patch has been released by the project maintainer. The project uses a rolling release model, so organizations should monitor the project repository for commits addressing this security issue. The maintainer was notified through a GitHub issue but has not yet responded.

Workarounds

• Implement strict input validation at the application perimeter, rejecting any requests containing shell metacharacters (;, |, &, $, backticks, etc.)
• Use network segmentation to isolate the vulnerable service from critical infrastructure components
• Deploy application-level sandboxing or containerization to limit the impact of successful exploitation
• If possible, modify the local deployment to use parameterized command execution methods (e.g., subprocess.run() with shell=False and argument lists) instead of string concatenation

# Example: Network-level mitigation using iptables to restrict access
# Limit access to the simple-openstack-mcp service to trusted IP ranges only
iptables -A INPUT -p tcp --dport <SERVICE_PORT> -s <TRUSTED_IP_RANGE> -j ACCEPT
iptables -A INPUT -p tcp --dport <SERVICE_PORT> -j DROP