{"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":0.00151,"epssPercentile":0.04674,"aliases":["GHSA-f5pj-2738-996m"],"ecosystem":"go","ingestedAt":"2026-08-25T16:28:51.169Z","slug":"CVE-2026-55580","body":"## Overview\n\nmcp-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-55580)\n\nAffected packages:\n\n- `github.com/sonirico/mcp-shell < 0.6.0`\n\nPatched in:\n\n- `github.com/sonirico/mcp-shell 0.6.0`\n\nSource: https://github.com/advisories/GHSA-f5pj-2738-996m","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}