CVE-2026-86083

n8n: Expression Sandbox Escape via Shared Builtin Tampering and Code-Printer Injection Leads to Code Execution

State: Published
Severity: 7.7 High
Published: Sep 8, 2026
Updated: Sep 9, 2026
Reserved: Sep 4, 2026

Description

n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the legacy expression engine generated source text by calling the mutable global JSON.stringify while printing synthetic string literals and interpolating timezone data. An expression could replace JSON.stringify and cause later generated source to contain executable attacker-controlled code. The affected code-generation paths include packages/@n8n/expression-runtime/src/bridge/isolated-vm-bridge.ts and packages/@n8n/tournament/src/ExpressionBuilder.ts, and the issue does not affect the vm expression engine. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.

Scores

CVSS	Score	Vector	Source
4.0	7.7 High	CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	GitHub_M

Weaknesses

CWE-94 Improper Control of Generation of Code ('Code Injection')

Affected Products

Product	Versions
n8nn8n-io	>= 2.38.0, < 2.38.2Affected >= 2.0.0, < 2.37.7Affected < 1.123.76Affected

References

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