CVE-2026-85169: n8n before 1.123.73 Remote Code Execution via $fromAI Prototype Leak

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-03 · updated 2026-10-29
Weakness: CWE-94

Description

n8n versions before 1.123.73, 2.35.4, and 2.36.2 contain an expression sandbox escape in the $fromAI handler. $fromAI resolved a caller-supplied placeholder name without requiring it to be an own property and admitted reserved keys; against a primitive input value it returned a live host-prototype reference. An attacker with workflow-build privilege can walk the prototype chain to the Function constructor and compile/execute arbitrary code in the main n8n process, leading to remote code execution.

Affected products

n8n-io n8n: before 1.123.73; from 2.0.0 before 2.35.4; from 2.36.0 before 2.36.2 — fixed in 1.123.73, 2.35.4, 2.36.2
n8n-io n8n: before 1.123.73 — fixed in 1.123.73

How to fix

Upgrade to a fixed version: n8n-io n8n 1.123.73, 2.35.4, 2.36.2; n8n-io n8n 1.123.73. Check the vendor advisory for mitigations.

References

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