# CVE-2026-86076: n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution

> Attackers can execute arbitrary JavaScript and backend code via expression sandbox escape in n8n editor, requiring immediate upgrade.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Sep 2026
- **Updated:** 9 Sep 2026
- **Also known as:** GHSA-hw8v-xxg5-vvvx, MINI-2q86-mx79-583j, ROOT-APP-NPM-CVE-2026-86076

## What is CVE-2026-86076?

CVE-2026-86076 is a high-severity code injection vulnerability in N8n N8n, published on 8 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-86076?

6 open source packages ship an affected version, including n8n. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `n8n` | npm | All versions | 1.123.76 |
| `n8n` | npm | All versions | 1.123.76 |
| `n8n` | npm | From 2.0.0 | 2.37.7 |
| `n8n` | npm | From 2.0.0 | 2.37.7 |
| `n8n` | npm | From 2.38.0 | 2.38.2 |
| `n8n` | npm | From 2.38.0 | 2.38.2 |

Products: N8n N8n.

## How do I fix CVE-2026-86076?

Upgrade n8n to a fixed version for your release line: 1.123.76, 2.37.7 or 2.38.2.

## Is CVE-2026-86076 being exploited?

There is no known exploitation of CVE-2026-86076 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-86076 — n8n expression sandbox escape via class-field __sanitize rebinding (backend RCE). Verified v2.37.6 (uid=node) / v2.37.7. (github_poc): https://github.com/Boreas37/CVE-2026-86076-PoC

## Other vulnerabilities in N8n N8n

- [CVE-2025-68613](https://insights.sbomify.com/CVE-2025-68613/): n8n Improper Control of Dynamically-Managed Code Resources (critical 10.0, exploited in the wild)
- [CVE-2026-21877](https://insights.sbomify.com/CVE-2026-21877/): n8n is vulnerable to Remote Code Execution via Arbitrary File Write (critical 10.0)
- [CVE-2026-21858](https://insights.sbomify.com/CVE-2026-21858/): n8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Handling (critical 10.0)
- [CVE-2026-1470](https://insights.sbomify.com/CVE-2026-1470/): n8n Unsafe Workflow Expression Evaluation Allows Remote Code Execution (critical 9.9)
- [CVE-2025-68668](https://insights.sbomify.com/CVE-2025-68668/): n8n Vulnerable to Arbitrary Command Execution in Pyodide based Python Code Node (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86076 and fix it if it is affected.

What it is: CVE-2026-86076 is a high-severity code injection vulnerability in N8n N8n, published on 8 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-86076 in the wild and no public exploit code.

Affected packages and fixed versions:
- n8n (npm): affected all versions; fixed in 1.123.76
- n8n (npm): affected all versions; fixed in 1.123.76
- n8n (npm): affected from 2.0.0; fixed in 2.37.7
- n8n (npm): affected from 2.0.0; fixed in 2.37.7
- n8n (npm): affected from 2.38.0; fixed in 2.38.2
- n8n (npm): affected from 2.38.0; fixed in 2.38.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-86076/ (Markdown: https://insights.sbomify.com/CVE-2026-86076/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86076
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86076
- OSV: https://osv.dev/vulnerability/CVE-2026-86076

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86076/
Summaries are generated and may contain mistakes; the official description above is the record.