GHSA-HX4H-VR3M-45VH
n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service
Description
## Impact An authenticated user able to create or edit a workflow expression could abuse the expression engine's array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process, leading to a denial of service. Both self-hosted and cloud instances running the VM expression engine are affected. ## Patches The issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict n8n instance access to fully trusted users only. - Disable the VM expression engine if an alternative is available for your deployment. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Affected products and versions
1| Product | Source | Version range | Status |
|---|---|---|---|
| GitHub Advisory | Before 1.123.67 · Fixed in 1.123.67 | affected | |
| 2.32.0 to < 2.32.1 · Fixed in 2.32.1 | affected | ||
| 2.0.0-rc.0 to < 2.31.5 · Fixed in 2.31.5 | affected |