{"apiVersion":"1.0","identifier":"CVE-2026-55580","description":"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.","publishedAt":"2026-08-25T16:16:55","lastModifiedAt":"2026-08-25T17:17:32","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55580","cvssScore":8.6,"cvssVector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","epssProbability":0.00151,"riskScore":0.87,"affectedProduct":"mcp-shell","affectedVersions":"<0.6.0","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-55580","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-55580","en":"https://www.redsauce.net/en/cves/CVE-2026-55580","fr":"https://www.redsauce.net/fr/cves/CVE-2026-55580","pt":"https://www.redsauce.net/pt/cves/CVE-2026-55580","de":"https://www.redsauce.net/de/cves/CVE-2026-55580","sk":"https://www.redsauce.net/sk/cves/CVE-2026-55580","el":"https://www.redsauce.net/el/cves/CVE-2026-55580"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-55580"}}