CVE-2026-110842
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.
- Score
- CVSS 4.0 7.7 High
- Status
- Deferred - disclosure@vulncheck.com
- Published
- 2026-10-14
- Last modified
- 2026-10-15
- Weaknesses
- CWE-1321
Affected products
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-inter…
