CVE-2026-110842
n8n
- Severity
- High
- Published
- October 14, 2026
- Last modified
- October 15, 2026
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.
CVSS 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
Weakness
References
Listed in
More n8n CVEs
Unauthenticated attackers can omit this identifier in requests to webhook, form, or MCP routes to execute workflows in unrelated projects under those projects' credentials.
n8n versions before 2.32.1 contain a server-side request forgery protection bypass vulnerability in the MCP Client node that allows authenticated users to bypass SSRF protections.
n8n before 2.29.8 and 2.30.x before 2.30.1 (affected from 2.27.0, when the OAuth 2.1 consent and token-issuance flow was introduced) does not verify that the authenticated user has access to the workflow…
The AI Agents feature did not enforce the Allowed HTTP Request Domains restriction configured on credentials when an MCP tool was pointed at an arbitrary URL, allowing a member-level user with use-only…
2.17.4, and 2.18.1, the MCP OAuth client registration endpoint accepted unauthenticated requests and stored client data without adequate resource controls.