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OpenAdvisories
High · 8.7 Public exploit CVE-2026-86076 EUVD-2026-74280GHSA-hw8v-xxg5-vvvx

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

Published Sep 8, 2026 · Updated Sep 9, 2026 · Assigned by GitHub_M

Vendor: n8n-io Product: n8n Package: n8n Ecosystem: npm

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.

Affected products

VendorProductAffectedFixed
n8n-io n8n >= 2.38.0, < 2.38.2, >= 2.0.0, < 2.37.7, < 1.123.76 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

  • Boreas37/CVE-2026-86076-PoC ★ 1 · Oct 24, 2026

    CVE-2026-86076 — n8n expression sandbox escape via class-field __sanitize rebinding (backend RCE). Verified v2.37.6 (uid=node) / v2.37.7.

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Affected packages

EcosystemPackageAffectedFixedRecord
npm n8n < 1.123.76 1.123.76 GHSA-hw8v-xxg5-vvvx
npm n8n >= 2.38.0, < 2.38.2 2.38.2 GHSA-hw8v-xxg5-vvvx
npm n8n >= 2.0.0, < 2.37.7 2.37.7 GHSA-hw8v-xxg5-vvvx

Advisories 1

References