CVE-2026-118678
Deferred Deferred - Pending Action

Prototype Pollution in n8n Workflow Connections

Vulnerability report for CVE-2026-118678, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-10-28

Last updated on: 2026-10-28

Assigner: VulnCheck

Description

n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as __proto__ to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.

CVSS Scores

EPSS Scores

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Meta Information

Published
2026-10-28
Last Modified
2026-10-28
Generated
2026-10-28
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
n8n-io n8n 0
n8n-io n8n 2.42.0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-1321 The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

Attack-Flow Graph

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EPSS Chart