CVE-2026-126391 · AI agents & MCP
NO FIX YET · SEE WHAT TO DO
n8n before 1.123.89 lets authenticated users escape the workflow expression sandbox through crafted JavaScript property references. An attacker who can create or modify workflows can execute arbitrary code on the n8n host.
first public Oct 28, 2026 · 1 source
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Any self-hosted n8n instance below 1.123.89 where users can create or modify workflows is exposed, since the flaw is in expression evaluation inside workflows. Instances where only fully trusted administrators can edit workflows face less risk. unknown whether managed n8n cloud is patched by the vendor.
Not affected if managed-hosting, workflow-editing-restricted
Who cares n8n, self-hosted, workflow-automation
n8n --version or the n8n instance settings page.1.123.89n8n before 1.123.89 contains an insufficient isolation vulnerability in workflow expression evaluation that allows authenticated users to escape the sandbox. Attackers with permission to create or modify workflows can craft expressions referencing unexpected JavaScript properties to execute arbitrary code on the n8n host.
This page as .md · .json · CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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