---
title: "CVE-2026-118678: n8n - Prototype Pollution"
description: "n8n < 2.41.4 and 2.42.x < 2.42.1 contains a prototype pollution vulnerability caused by saving workflows with specially named connection keys, letting low-privileged users cause server errors by altering built-in object behavior, exploit requires low-privileged user access."
url: https://panop.io/threat-heartbeat/CVE-2026-118678/
---

# CVE-2026-118678 n8n - Prototype Pollution

n8n < 2.41.4 and 2.42.x < 2.42.1 contains a prototype pollution vulnerability caused by saving workflows with specially named connection keys, letting low-privileged users cause server errors by altering built-in object behavior, exploit requires low-privileged user access.

CVSS base score 7.1 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-118678)

## Details

Type

Prototype Pollution

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

Published

28 October 2026

Updated

29 October 2026

Weakness

[CWE-1321](https://cwe.mitre.org/data/definitions/1321.html)

## Vendor fix

Upgrade to versions 2.41.4 or 2.42.1 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-118678](https://nvd.nist.gov/vuln/detail/CVE-2026-118678)
- [https://github.com/n8n-io/n8n/security/advisories/GHSA-fvv4-gmv9-xqf5](https://github.com/n8n-io/n8n/security/advisories/GHSA-fvv4-gmv9-xqf5)
- [https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-dos-via-workflow-history-compaction](https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-dos-via-workflow-history-compaction)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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