{"id":"CVE-2026-110842","aliases":["EUVD-2026-101725","GHSA-5jr4-xmvf-frmj","GHSA-fm6v-qhr5-4c32"],"status":"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.","severity":{"version":"4.0","score":7.7,"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00312,"percentile":0.24463,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1321"],"published":"2026-10-14T22:52:17Z","modified":"2026-11-02T02:46:18Z","products":[{"vendor":"n8n-io","product":"n8n"}],"references":[{"url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-5jr4-xmvf-frmj","tags":["vendor-advisory","advisory"]},{"url":"https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-via-mcp-workflow-validation-interpreter","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-110842","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-fm6v-qhr5-4c32"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/110xxx/CVE-2026-110842.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-110842","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.","status":"published","published":"2026-10-14T22:52:17.341Z","modified":"2026-10-15T13:44:50.036Z","cvss":[{"version":"4.0","score":7.7,"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","level":"high","assessor":"cna"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T13:34:26.24368Z"}],"euvd":[{"id":"EUVD-2026-101725","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.","status":"published","published":"2026-10-14T22:52:17Z","modified":"2026-10-15T13:44:50Z","cvss":[{"version":"4.0","score":7.7,"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","level":"high"}],"updated_at":"2026-11-02T17:00:14.584665Z"}],"ghsa":[{"id":"GHSA-fm6v-qhr5-4c32","title":"n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability in the...","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.","status":"published","published":"2026-10-15T00:31:17Z","modified":"2026-10-15T00:31:21Z","cvss":[{"version":"4.0","score":7.7,"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/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","level":"high"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T15:13:29.914076Z"}],"nvd":[{"id":"CVE-2026-110842","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.","status":"published","published":"2026-10-14T23:17:24.637Z","modified":"2026-10-15T14:17:20.867Z","cvss":[{"version":"4.0","score":7.7,"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/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","level":"high","assessor":"secondary"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T14:12:59.328869Z"}],"osv":[{"id":"CVE-2026-110842","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.","status":"published","published":"2026-10-14T22:52:17.341Z","modified":"2026-11-02T02:46:18.224338969Z","cvss":[{"version":"4.0","score":7.7,"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","level":"high"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T15:44:55.61515Z"}]}}