CVE-2026-7593: Sunwood Command Executor RCE Vulnerability

CVE-2026-7593 Overview

CVE-2026-7593 is an operating system command injection vulnerability in Sunwood-ai-labs command-executor-mcp-server through version 0.1.0. The flaw resides in the execute_command function within src/index.ts, part of the Model Context Protocol (MCP) Interface component. Attackers can manipulate input to inject arbitrary operating system commands without authentication. Remote exploitation is possible across the network, and the exploit has been disclosed publicly. The maintainer received an early issue report but has not responded as of disclosure. The weakness is classified under CWE-77 (Improper Neutralization of Special Elements used in a Command).

Critical Impact
Unauthenticated remote attackers can inject operating system commands through the MCP execute_command interface, leading to arbitrary command execution on the host running the server.

Affected Products

Sunwood-ai-labs command-executor-mcp-server versions up to and including 0.1.0
The execute_command function in src/index.ts
MCP Interface component exposed by the server

Discovery Timeline

2026-05-01 - CVE-2026-7593 published to NVD
2026-05-05 - Last updated in NVD database

Technical Details for CVE-2026-7593

Vulnerability Analysis

The vulnerability exists in the execute_command handler exposed by the Model Context Protocol (MCP) server. The handler accepts a command string from clients and passes it to the underlying operating system shell without adequate neutralization of shell metacharacters. An attacker can supply payloads containing characters such as ;, &&, |, or backticks to chain additional commands. Because the MCP server is reachable over the network and requires no authentication, any client able to send MCP requests can trigger execution. The EPSS probability is 2.177% with a percentile of 84.45, indicating elevated relative likelihood of exploitation activity. The public GitHub repository hosts both the vulnerable source and a corresponding GitHub Issue Discussion describing the flaw.

Root Cause

The root cause is improper neutralization of special elements used in a command, mapped to [CWE-77]. The execute_command implementation concatenates or forwards user-controlled strings into a shell execution call without argument array separation, allowlisting, or escaping. MCP servers are designed to expose tool capabilities to large language model agents, so the command interface is intentionally broad, which amplifies the impact of missing validation.

Attack Vector

Exploitation occurs over the network through the MCP transport. An attacker connects to the exposed MCP server and invokes the execute_command tool with a payload that combines a benign command with appended shell metacharacters and additional commands. The injected commands run with the privileges of the server process. In agentic AI deployments, indirect prompt injection against the connected language model can also coerce the agent into invoking the vulnerable tool with attacker-chosen arguments.

No verified exploit code is published. Refer to the VulDB Vulnerability Details and the GitHub PoC Repository for technical context.

Detection Methods for CVE-2026-7593

Indicators of Compromise

Child processes spawned by the Node.js command-executor-mcp-server runtime that are inconsistent with expected developer commands, such as sh -c, bash -c, curl, wget, or nc.
Outbound network connections from the MCP server host to unfamiliar IP addresses or domains shortly after MCP requests.
MCP request payloads to execute_command containing shell metacharacters (;, &&, ||, |, backticks, $()).

Detection Strategies

Inspect application logs for execute_command invocations and flag arguments containing shell control characters or chained commands.
Apply process-tree analytics to identify Node.js parents spawning shells that subsequently launch reconnaissance or download utilities.
Correlate MCP request timestamps with new outbound network flows or new file writes under user-writable paths.

Monitoring Recommendations

Forward MCP server stdout, stderr, and request logs to a centralized logging platform for retention and search.
Enable command-line auditing on the host (auditd execve rules on Linux, Sysmon Event ID 1 on Windows) to capture all child process executions.
Alert on any execution of interactive shells or interpreters by the MCP server service account outside of approved workflows.

How to Mitigate CVE-2026-7593

Immediate Actions Required

Remove command-executor-mcp-server from any internet-reachable interface and restrict access to localhost or an authenticated reverse proxy.
Stop or uninstall the server in production environments until a patched release is available.
Audit recent MCP request logs and host process history for signs of command injection or unauthorized execution.

Patch Information

No vendor patch is available at the time of publication. The maintainer was notified through an issue report but has not responded. Track the GitHub Issue Discussion and the GitHub PoC Repository for updates. Until a fixed version is released, treat all deployments of versions through 0.1.0 as vulnerable.

Workarounds

Run the MCP server inside a hardened container or sandbox with no network egress and a read-only filesystem.
Replace the shell-based execution path with an allowlist of permitted commands and pass arguments as separate array elements rather than a single shell string.
Enforce least privilege by running the service under a dedicated unprivileged account with no sudo rights.
Add a request validation layer that rejects payloads containing shell metacharacters before they reach execute_command.

bash

# Example: restrict the MCP server to localhost and run as an unprivileged, sandboxed user
sudo useradd -r -s /usr/sbin/nologin mcpsvc
sudo -u mcpsvc node ./build/index.js --bind 127.0.0.1 --port 8080
# Block outbound egress from the service account using nftables
sudo nft add rule inet filter output skuid mcpsvc drop