CVE-2026-86076

n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution

Published Sep 8, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-hw8v-xxg5-vvvx n8n: Expression Sandbox Escape via Class-Field Sanitizer Rebinding Can Lead to Code Execution
History
Type Values Removed Values Added
First Time appeared N8n
N8n n8n
CPEs cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*
Vendors & Products N8n
N8n n8n
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution
Weaknesses CWE-94
References
Metrics cvssV4_0

{'score': 8.7, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 9, 2026, 3:33 PM
Reserved
Sep 4, 2026, 7:34 PM
Status
Analyzed
Published
Sep 8, 2026, 10:19 PM
Modified
Sep 11, 2026, 6:20 PM