CVE-2026-118678

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 v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
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

Configurations

No configuration.

History

28 Oct 2026, 19:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-28 19:17

Updated : 2026-10-29 21:17

NVD link : CVE-2026-118678

Mitre link : CVE-2026-118678

CVE.ORG link : CVE-2026-118678

JSON object : View

Products Affected

No product.

CWE

CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

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