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GHSA-pm35-fqvh-cq5g CVE-2026-65591

n8n: Legacy Expression Evaluator Sanitizer Bypass Leads to Authenticated Code Execution

High npm
Severity
0.0 / 10
High · CVSS 4.0
Exploit chance (EPSS)
0.69%
Chance of exploitation in the next 30 days. Higher than 52.97% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-917 Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
Fix
1.123.64
Upgrade n8n to this version or later

Description

Impact

The legacy expression evaluator's computed-member sanitizer can be bypassed by an authenticated user with workflow create or modify permissions. Successful exploitation grants the attacker host-level code execution as the n8n process.

The legacy expression engine is the default engine in affected versions.

Patches

The issue has been fixed in n8n versions 1.123.64, 2.29.8, and 2.30.1. 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.
  • Switch to the non-legacy expression engine by setting N8N_EXPRESSION_ENGINE=vm.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Affected versions

npm

PackageVulnerableFixed in
n8n
< 1.123.64
1.123.64
n8n
>= 2.30.0, < 2.30.1
2.30.1
n8n
>= 2.0.0-rc.0, < 2.29.8
2.29.8

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

n8n npm → 1.123.64

npm
npm install n8n@1.123.64
yarn
yarn add n8n@1.123.64
pnpm
pnpm add n8n@1.123.64

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
Low
User interaction
None
Confidentiality (vulnerable system)
High
Integrity (vulnerable system)
High
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
High
Integrity (subsequent systems)
High
Availability (subsequent systems)
Low

CVSS 3.1 8.8

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Weakness

CWE-917: Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')

The product constructs all or part of an expression language (EL) statement in a framework such as a Java Server Page (JSP) using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended EL statement before it is executed.

How to prevent it
  • Architecture and Design: Avoid adding user-controlled data into an expression interpreter when possible.
  • Implementation: If user-controlled data must be added to an expression interpreter, one or more of the following should be performed: Validate that the user input will not evaluate as an expression Encode the user input in a way that ensures it is not evaluated as an expression
  • System Configuration, Operation: The framework or tooling might allow the developer to disable or deactivate the processing of EL expressions, such as setting the isELIgnored attribute for a JSP page to "true".

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-v98v-ff95-f3cp
n8n Vulnerable to Remote Code Execution via Expression Injection
High Known exploited Also affects n8n
GHSA-qgpw-8g46-w95v
n8n: Git Node branch.<name>.remote Config Key Bypasses Sandbox Path Restriction, Enabling Local Git Repository Read
Medium Also affects n8n
GHSA-65xw-2v52-jhxc
n8n: Cross-User Active Workflow ID and Lifecycle Event Disclosure via Missing userId Filter
Medium Also affects n8n
GHSA-pq6c-vh67-xpm3
n8n: Log Streaming Event Destinations Decrypt Generic-Auth Credentials Without Ownership Check
Medium Also affects n8n
GHSA-cqr2-h44g-v75v
n8n: Cross-Tenant Project-Member PII Disclosure via Missing Per-Project Scope Check on Role Assignment Endpoints
Medium Also affects n8n
GHSA-pf83-w3f9-8m37
n8n: Disabled OIDC SSO Endpoints Remain Active and Issue Valid Sessions
Medium Also affects n8n
GHSA-6xcw-7xm6-48c6
n8n: Expression Sandbox Escape via Shared Builtin Tampering and Code-Printer Injection Leads to Code Execution
High Also affects n8n
GHSA-34ff-336r-5q23
n8n: Domain-Restriction Bypass via Unguarded Model-Search Endpoint in OpenAI Chat Model Node
Medium Also affects n8n
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