WS-2026-0097
Published:September 30, 2026
Updated:October 07, 2026
n8n MCP workflow-validation interpreter (the @n8n/workflow-sdk AST interpreter) allowed workflow code to mutate shared prototypes. Affects n8n 2.12.0 to 2.41.3 and 2.42.0 (@n8n/workflow-sdk 0.2.0 to 0.34.0 and 0.35.0); fixed in n8n 2.41.4 / 2.42.1 (@n8n/workflow-sdk 0.34.1 / 0.35.1).
Affected Packages
https://github.com/n8n-io/n8n.git (GITHUB):
Affected version(s) =n8n@2.42.0 <n8n@2.42.1Fix Suggestion:
Update to version n8n@2.42.1https://github.com/n8n-io/n8n.git (GITHUB):
Affected version(s) >=n8n@2.9.0 <n8n@2.41.4Fix Suggestion:
Update to version n8n@2.41.4n8n (NPM):
Affected version(s) >=2.12.0 <2.41.4Fix Suggestion:
Update to version 2.41.4n8n (NPM):
Affected version(s) =2.42.0 <2.42.1Fix Suggestion:
Update to version 2.42.1@n8n/workflow-sdk (NPM):
Affected version(s) =0.35.0 <0.35.1Fix Suggestion:
Update to version 0.35.1@n8n/workflow-sdk (NPM):
Affected version(s) >=0.2.0 <0.34.1Fix Suggestion:
Update to version 0.34.1Related Resources (2)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')