{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-110842", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-10-14T22:12:22.055Z", "datePublished": "2026-10-14T22:52:17.341Z", "dateUpdated": "2026-10-14T22:52:17.341Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-10-14T22:52:17.341Z"}, "datePublic": "2026-09-30T00:00:00.000Z", "title": "n8n before 2.41.4 and 2.42.1 Prototype Pollution via MCP Workflow-Validation Interpreter", "descriptions": [{"lang": "en", "value": "n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability in the MCP workflow-validation tool, whose interpreter evaluates caller-supplied code in the main process, reads inherited properties, and permits assignment onto shared prototypes. An authenticated member holding only a workflow:read grant can replace a built-in method with one returning a truthy value so server-side permission checks accept unheld scopes, enabling takeover of owner accounts not protected by MFA."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')", "cweId": "CWE-1321", "type": "CWE"}]}], "affected": [{"vendor": "n8n-io", "product": "n8n", "defaultStatus": "unaffected", "packageURL": "pkg:npm/n8n", "versions": [{"version": "0", "status": "affected", "versionType": "semver", "lessThan": "2.41.4"}, {"version": "2.42.0", "status": "affected", "versionType": "semver", "lessThan": "2.42.1"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:n8n:n8n:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.41.4"}, {"vulnerable": true, "criteria": "cpe:2.3:a:n8n:n8n:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.42.0", "versionEndExcluding": "2.42.1"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 7.7, "baseSeverity": "HIGH"}}], "references": [{"url": "https://github.com/n8n-io/n8n/security/advisories/GHSA-5jr4-xmvf-frmj", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-5jr4-xmvf-frmj)"}, {"name": "VulnCheck Advisory: n8n before 2.41.4 and 2.42.1 Prototype Pollution via MCP Workflow-Validation Interpreter", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-via-mcp-workflow-validation-interpreter"}], "credits": [{"lang": "en", "value": "sm1ee", "type": "reporter"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:npm/n8n", "product": "n8n", "vendor": "n8n-io", "versions": [{"lessThan": "2.41.4", "status": "affected", "version": "0", "versionType": "semver"}, {"lessThan": "2.42.1", "status": "affected", "version": "2.42.0", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability in the MCP workflow-validation tool, whose interpreter evaluates caller-supplied code in the main process, reads inherited properties, and permits assignment onto shared prototypes. An authenticated member holding only a workflow:read grant can replace a built-in method with one returning a truthy value so server-side permission checks accept unheld scopes, enabling takeover of owner accounts not protected by MFA."}], "id": "CVE-2026-110842", "lastModified": "2026-10-14T23:17:24.743", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.7, "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": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/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": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-10-14T23:17:24.637", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/n8n-io/n8n/security/advisories/GHSA-5jr4-xmvf-frmj"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-via-mcp-workflow-validation-interpreter"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-1321"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

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