CVE-2026-55580

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-55580", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-16T23:18:03.169Z", "datePublished": "2026-08-25T15:42:36.474Z", "dateUpdated": "2026-08-25T16:08:10.442Z"}, "containers": {"cna": {"title": "mcp-shell \u2014 Security Disabled by Default in Bare-Binary Deploy Path + Shell Interpreter in Secure-Mode Allowlist", "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"}]}], "metrics": [{"cvssV4_0": {"attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.6, "baseSeverity": "HIGH", "vectorString": "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", "version": "4.0"}}], "references": [{"name": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m"}, {"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": "2026-08-25T15:42:36.474Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-f5pj-2738-996m", "discovery": "UNKNOWN"}}, "adp": [{"references": [{"url": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-25T16:07:52.580459Z", "id": "CVE-2026-55580", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-25T16:08:10.442Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-55580", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-08-25T16:07:52.580459Z"}}}], "references": [{"url": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-25T16:08:04.282Z"}}], "cna": {"title": "mcp-shell \u2014 Security Disabled by Default in Bare-Binary Deploy Path + Shell Interpreter in Secure-Mode Allowlist", "source": {"advisory": "GHSA-f5pj-2738-996m", "discovery": "UNKNOWN"}, "metrics": [{"cvssV4_0": {"version": "4.0", "baseScore": 8.6, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "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", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH"}}], "affected": [{"vendor": "sonirico", "product": "mcp-shell", "versions": [{"status": "affected", "version": "< 0.6.0"}]}], "references": [{"url": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m", "name": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/sonirico/mcp-shell/pull/16", "name": "https://github.com/sonirico/mcp-shell/pull/16", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/sonirico/mcp-shell/commit/f31377fce6ec31114e5a4398c0e5270552bce09f", "name": "https://github.com/sonirico/mcp-shell/commit/f31377fce6ec31114e5a4398c0e5270552bce09f", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/sonirico/mcp-shell/releases/tag/v0.6.0", "name": "https://github.com/sonirico/mcp-shell/releases/tag/v0.6.0", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "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."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-78", "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-25T15:42:36.474Z"}}}, "cveMetadata": {"cveId": "CVE-2026-55580", "state": "PUBLISHED", "dateUpdated": "2026-08-25T16:08:10.442Z", "dateReserved": "2026-06-16T23:18:03.169Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-08-25T15:42:36.474Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "mcp-shell", "vendor": "sonirico", "versions": [{"status": "affected", "version": "< 0.6.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-55580", "lastModified": "2026-09-09T21:07:31.353", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.6, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55580", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-08-25T16:07:52.580459Z", "version": "2.0.3"}}]}, "published": "2026-08-25T16:16:55.317", "references": [{"source": "security-advisories@github.com", "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-f5pj-2738-996m"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/sonirico/mcp-shell/security/advisories/GHSA-f5pj-2738-996m"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-78"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,0.6.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "mcp-shell", "source": "cna", "vendor": "sonirico"}, "product": "mcp-shell", "vendor": "sonirico"}], "created": "2026-08-25T17:45:04.634525+00:00", "updated": "2026-08-25T21:30:06.890430+00:00", "vendors": ["sonirico", "sonirico$PRODUCT$mcp-shell"]}