Vulnerability · Published Oct 14, 2026 · Assigned by VulnCheck

CVE-2026-110842n8n before 2.41.4 and 2.42.1 Prototype Pollution via MCP Workflow-Validation Interpreter

High 7.7

In plain English

A high-severity prototype pollution in n8n from n8n-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 4.0)7.7High

Exploit odds (30 days)0.3%top 75.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
n8n-io	n8n	0 – before 2.41.42.42.0 – before 2.42.1

Weakness: CWE-1321 · 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

References

GitHub Security Advisory (GHSA-5jr4-xmvf-frmj) vendor-advisory
VulnCheck Advisory: n8n before 2.41.4 and 2.42.1 Prototype Pollution via MCP Workflow-Validation Interpreter third-party-advisory