CVE-2026-86078: n8n

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

n8n is an open source workflow automation platform. Prior to 2.37.7 and 2.38.2, the Instance AI workflow summary used node names and connection keys from stored workflows as ordinary object keys. A workflow submitted through the REST API could contain __proto__ or constructor, causing nested writes to reach Object.prototype in the main n8n process and disrupt later requests. The affected function is summarizeWorkflowStructure in packages/@n8n/instance-ai/src/tools/workflows/summarize-workflow.ts. This issue is fixed in versions 2.37.7 and 2.38.2.

Affected products

• n8n n8n: before 2.37.7 (fixed in 2.37.7); from 2.38.0, before 2.38.2 (fixed in 2.38.2)

Published 2026-09-08. Last modified 2026-09-11.