---
id: CVE-2026-55580
title: >-
  mcp-shell is an MCP server for running shell commands securely, auditably, and
  on demand
summary: >-
  mcp-shell is an MCP server for running shell commands securely, auditably, and
  on demand. Prior to 0.6.0, config.go initializes Security.Enabled to false,
  and when MCP_SHELL_SEC_CONFIG_FILE is unset, main.go starts the documented
  bare-bi…
severity: high
cwe:
  - CWE-78
vendor: sonirico
product: github.com/sonirico/mcp-shell
affected:
  - github.com/sonirico/mcp-shell < 0.6.0
patched:
  - github.com/sonirico/mcp-shell 0.6.0
published: '2026-08-25'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:07:31.353'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55580'
references:
  - url: >-
      https://github.com/sonirico/mcp-shell/commit/f31377fce6ec31114e5a4398c0e5270552bce09f
    label: security-advisories@github.com
  - url: 'https://github.com/sonirico/mcp-shell/pull/16'
    label: security-advisories@github.com
  - url: 'https://github.com/sonirico/mcp-shell/releases/tag/v0.6.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m
    label: security-advisories@github.com
  - url: >-
      https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-f5pj-2738-996m'
tags:
  - nvd
  - ghsa
  - go
epss: 0.00197
epssPercentile: 0.08319
aliases:
  - GHSA-f5pj-2738-996m
ecosystem: go
ingestedAt: '2026-08-25T16:28:51.169Z'
---

## Overview

mcp-shell is an MCP server for running shell commands securely, auditably, and on demand. Prior to 0.6.0, config.go initializes Security.Enabled to false, and when MCP_SHELL_SEC_CONFIG_FILE is unset, main.go starts the documented bare-binary deployment without a security policy. SecurityValidator.validateCommand in security.go then short-circuits and allows every command supplied to the shell_exec MCP tool, so an LLM connected over stdio can execute unrestricted OS commands as the mcp-shell process user. The README from-source installation and MCP client configuration omit MCP_SHELL_SEC_CONFIG_FILE, making the insecure state the documented default. This issue is fixed in version 0.6.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-55580)

Affected packages:

- `github.com/sonirico/mcp-shell < 0.6.0`

Patched in:

- `github.com/sonirico/mcp-shell 0.6.0`

Source: https://github.com/advisories/GHSA-f5pj-2738-996m