{"id":"GHSA-hx4h-vr3m-45vh","title":"n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service","summary":"n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service","severity":"medium","cwe":["CWE-1321"],"vendor":"n8n","product":"n8n","ecosystem":"npm","affected":["n8n < 1.123.67","n8n >= 2.32.0, < 2.32.1","n8n >= 2.0.0-rc.0, < 2.31.5"],"patched":["n8n 1.123.67","n8n 2.32.1","n8n 2.31.5"],"published":"2026-07-22","updated":"2026-07-22","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-hx4h-vr3m-45vh","references":[{"url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-hx4h-vr3m-45vh"},{"url":"https://github.com/n8n-io/n8n/commit/f69dfc6dd2178a14ea1624d2e1d403c2e755042f"},{"url":"https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.67"},{"url":"https://github.com/n8n-io/n8n/releases/tag/n8n@2.31.5"},{"url":"https://github.com/n8n-io/n8n/releases/tag/n8n@2.32.1"},{"url":"https://github.com/advisories/GHSA-hx4h-vr3m-45vh"}],"tags":["ghsa","npm"],"ingestedAt":"2026-07-22T23:07:32.844Z","slug":"GHSA-hx4h-vr3m-45vh","body":"## Overview\n\n## Impact\n\nAn 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.\n\nBoth self-hosted and cloud instances running the VM expression engine are affected.\n\n## Patches\n\nThe 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.\n\n## Workarounds\n\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Restrict n8n instance access to fully trusted users only.\n- Disable the VM expression engine if an alternative is available for your deployment.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.\n\n## Affected packages\n\n- `n8n < 1.123.67`\n- `n8n >= 2.32.0, < 2.32.1`\n- `n8n >= 2.0.0-rc.0, < 2.31.5`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `n8n 1.123.67`\n- `n8n 2.32.1`\n- `n8n 2.31.5`","depth":"sunlit","depthScore":28,"depthScoreParts":{"impact":27.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}