{"id":"CVE-2026-110842","state":"PUBLISHED","title":"n8n before 2.41.4 and 2.42.1 Prototype Pollution via MCP Workflow-Validation Interpreter","description":"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.","publishedAt":"2026-10-14T22:52:17.341Z","updatedAt":"2026-10-15T13:44:50.036Z","severity":{"score":7.7,"label":"High","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["n8n-io n8n"],"affected":[{"vendor":"n8n-io","product":"n8n","packageURL":"pkg:npm/n8n","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2.41.4","versionType":"semver"},{"version":"2.42.0","status":"affected","lessThan":"2.42.1","versionType":"semver"}]}],"references":["https://github.com/n8n-io/n8n/security/advisories/GHSA-5jr4-xmvf-frmj","https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-via-mcp-workflow-validation-interpreter"],"weaknesses":["CWE-1321"],"ingestedAt":"2026-10-29T20:10:33.477Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/110xxx/CVE-2026-110842.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-110842","state":"PUBLISHED","datePublished":"2026-10-14T22:52:17.341Z","dateUpdated":"2026-10-15T13:44:50.036Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-10-14T22:12:22.055Z"},"containers":{"cna":{"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."}],"affected":[{"vendor":"n8n-io","product":"n8n","packageURL":"pkg:npm/n8n","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2.41.4","versionType":"semver"},{"version":"2.42.0","status":"affected","lessThan":"2.42.1","versionType":"semver"}]}],"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)"},{"url":"https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-via-mcp-workflow-validation-interpreter","name":"VulnCheck Advisory: n8n before 2.41.4 and 2.42.1 Prototype Pollution via MCP Workflow-Validation Interpreter","tags":["third-party-advisory"]}],"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1321","lang":"en","description":"Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-14T22:52:17.341Z"},"datePublic":"2026-09-30T00:00:00.000Z","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"}]}]}],"credits":[{"lang":"en","value":"sm1ee","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-15T13:44:32.171824Z","id":"CVE-2026-110842","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T13:44:50.036Z"}}]}}}