medium6.5
CVE-2026-86078
n8n: Prototype Pollution via Workflow Structure Summary Can Lead to Denial of Service
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | n8n | >= 2.38.0, < 2.38.2 | 2.38.2 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| N8n | N8n | before 2.37.7 from 2.38.0 before 2.38.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-679f-58pq-4v2c
- https://github.com/n8n-io/n8n/security/advisories/GHSA-679f-58pq-4v2c
- https://nvd.nist.gov/vuln/detail/CVE-2026-86078
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2