CVE-2026-86078

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

MEDIUM
6.5
CVSS Score
Published: September 8, 2026 at 09:27 PM UTC
Updated: September 11, 2026 at 06:40 PM UTC
2 products affected across 2 vendorsN8NN8N

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

95%
v < 2.37.72.38.0 ≤ v < 2.38.2
Affected range stops below 2.37.7, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.38.2, so it looks safe — our inference, not a vendor statement
v < 2.37.7v < 2.38.2
Affected range stops below 2.37.7, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.38.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/n8n-io/n8n/security/advisories/GHSA-679f-58pq-4v2c
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/n8n-io/n8n/releases/tag/[email protected]
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/n8n-io/n8n/releases/tag/[email protected]

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-1321

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