{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-55581",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-06-16T23:18:03.169Z",
        "datePublished": "2026-08-25T15:40:10.992Z",
        "dateUpdated": "2026-08-25T15:40:10.992Z"
    },
    "containers": {
        "cna": {
            "title": "mcp-shell: Secure Mode Allowlist Bypass via Default `/bin/bash` Executable",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-78",
                            "lang": "en",
                            "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-183",
                            "lang": "en",
                            "description": "CWE-183: Permissive List of Allowed Inputs",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1188",
                            "lang": "en",
                            "description": "CWE-1188: Insecure Default Initialization of Resource",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "LOCAL",
                        "availabilityImpact": "HIGH",
                        "baseScore": 8.4,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "HIGH",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-3x77-wg38-92r3",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-3x77-wg38-92r3"
                },
                {
                    "name": "https://github.com/sonirico/mcp-shell/pull/16",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/sonirico/mcp-shell/pull/16"
                },
                {
                    "name": "https://github.com/sonirico/mcp-shell/commit/f31377fce6ec31114e5a4398c0e5270552bce09f",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/sonirico/mcp-shell/commit/f31377fce6ec31114e5a4398c0e5270552bce09f"
                },
                {
                    "name": "https://github.com/sonirico/mcp-shell/releases/tag/v0.6.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/sonirico/mcp-shell/releases/tag/v0.6.0"
                }
            ],
            "affected": [
                {
                    "vendor": "sonirico",
                    "product": "mcp-shell",
                    "versions": [
                        {
                            "version": "< 0.6.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-08-25T15:40:10.992Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "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."
                }
            ],
            "source": {
                "advisory": "GHSA-3x77-wg38-92r3",
                "discovery": "UNKNOWN"
            }
        }
    }
}