CVE-2026-55581

The record

mcp-shell is an MCP server for running shell commands securely, auditably, and on demand. Prior to 0.6.0, the default Docker security.yaml includes /bin/bash in allowed_executables, while security.go validates only the first token and checkBlockedPatternsAndCommands does not reject the shell command-mode flag -c. A caller of the shell_exec MCP tool can provide the command argument `/bin/bash -c <arbitrary-command>`, which passes validation and reaches executor.go, where parseCommand and exec.CommandContext execute the arbitrary command as mcpuser outside the intended allowlist. This issue is fixed in version 0.6.0.

Affected packages

Related vulnerabilities

• CVE-2026-96376 Improper Neutralization of Special Elements used in an OS Command ("OS Command… CWE-78
• CVE-2026-113732 virtualenv is a tool for creating isolated virtual python environments. CWE-78
• CVE-2026-113776 virtualenv is a tool for creating isolated virtual python environments. CWE-78
• CVE-2026-113726 virtualenv is a tool for creating isolated virtual python environments. CWE-78
• CVE-2026-113725 virtualenv is a tool for creating isolated virtual python environments. CWE-78
• CVE-2026-113722 virtualenv is a tool for creating isolated virtual python environments. CWE-78
• CVE-2026-112943 launch-editor allows users to open files with line numbers in editor from Node.js. CWE-78
• CVE-2026-112900 Pillow is a Python imaging library. CWE-78