CVE-2026-86076 — Vulnerability in n8n — CVE Details

HIGH

n8n: Expression Sandbox Escape via Class-Field Sanitizer Rebinding Can Lead to Code Execution

Published September 10, 2026Updated September 10, 2026Source: osv

Summary

## Impact The expression compiler's sanitizer resolved through a dynamically-scoped `this`, so a class field named `__sanitize` rebound it and reached the `Function` constructor. On the backend, any expression author could run code in the n8n process; in the editor preview, a member's expression could run as JavaScript in the session of whoever opened the workflow. The patch rejects reserved class-member names. ## Patches The issue has been fixed in n8n versions 1.123.76, 2.37.7, and 2.38.2. 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. - Avoid granting workflow-create or workflow-edit permissions to untrusted users. - Audit existing workflows for unexpected or unfamiliar expressions in node parameters. - Set `N8N_EXPRESSION_ENGINE=vm`. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Advisory Timeline

First published September 10, 2026 (32 days ago).
Last revised September 10, 2026 — 0 days after initial publication.

Remediation

Upgrade to the fixed version using your package manager.

npm

Update n8n to 1.123.76 or later

npm install n8n@1.123.76

npm

Update n8n to 2.37.7 or later

npm install n8n@2.37.7

npm

Update n8n to 2.38.2 or later

npm install n8n@2.38.2

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (3)

Affects 1 ecosystem: npm (1).

Package	Ecosystem	Affected	Fixed In
n8n	npm	All versions	1.123.76
n8n	npm	All versions	2.37.7
n8n	npm	All versions	2.38.2

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CWE-94
Code InjectionMITRE

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 9.5 score means for each attack dimension.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

—

Confidentiality

—

Integrity

—

Availability

—

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

References

Frequently Asked Questions

What is CVE-2026-86076?: n8n: Expression Sandbox Escape via Class-Field Sanitizer Rebinding Can Lead to Code Execution This vulnerability has been assigned a severity rating of HIGH (CVSS score: 9.5/10).
How do I check if my project is affected by CVE-2026-86076?: CVE-2026-86076 affects n8n. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2026-86076 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score

9.5

Exploitation is straightforward and causes maximum impact. Patch immediately.

Also Known As

GHSA-hw8v-xxg5-vvvx

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