CVE-2026-86078

n8n: Prototype Pollution via Workflow Structure Summary Can Lead to Denial of Service

Published Sep 8, 2026 CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-679f-58pq-4v2c n8n: Prototype Pollution via Workflow Structure Summary Can Lead to Denial of Service
History
Type Values Removed Values Added
First Time appeared N8n
N8n n8n
CPEs cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*
Vendors & Products N8n
N8n n8n
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title n8n: Prototype Pollution via Workflow Structure Summary Can Lead to Denial of Service
Weaknesses CWE-1321
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 9, 2026, 4:03 PM
Reserved
Sep 4, 2026, 7:34 PM
Status
Analyzed
Published
Sep 8, 2026, 10:19 PM
Modified
Sep 11, 2026, 6:21 PM