CVE-2026-55581

{"id": "CVE-2026-55581", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55581", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-08-25T19:01:36.178820Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.4, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.5}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "sonirico", "product": "mcp-shell", "versions": [{"status": "affected", "version": "< 0.6.0"}]}]}], "published": "2026-08-25T16:16:55.470", "references": [{"url": "https://github.com/sonirico/mcp-shell/commit/f31377fce6ec31114e5a4398c0e5270552bce09f", "source": "security-advisories@github.com"}, {"url": "https://github.com/sonirico/mcp-shell/pull/16", "source": "security-advisories@github.com"}, {"url": "https://github.com/sonirico/mcp-shell/releases/tag/v0.6.0", "source": "security-advisories@github.com"}, {"url": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-3x77-wg38-92r3", "source": "security-advisories@github.com"}, {"url": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-3x77-wg38-92r3", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-78"}, {"lang": "en", "value": "CWE-183"}, {"lang": "en", "value": "CWE-1188"}]}], "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."}], "lastModified": "2026-09-09T21:07:31.353", "sourceIdentifier": "security-advisories@github.com"}