GHSA-hx4h-vr3m-45vh: n8n Denial of Service Vulnerability

MODERATE
Share
CWE-1321
Published
Advisory Summary

GHSA-hx4h-vr3m-45vh is a MODERATE denial of service vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting n8n libraries in the npm ecosystem. The issue involves prototype pollution via vm expression engine sandbox escape leads to denial of service. Remediation is available by upgrading affected packages to version 1.123.67, 2.32.1, 2.31.5.

GHSA-hx4h-vr3m-45vh at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-hx4h-vr3m-45vh
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product n8n
Package Ecosystem npm
Published Date
Last Updated

How to Fix GHSA-hx4h-vr3m-45vh

To remediate this vulnerability, upgrade all affected n8n dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

n8n fixed: 1.123.67 
npm install n8n@1.123.67
n8n fixed: 2.32.1 
npm install n8n@2.32.1
n8n fixed: 2.31.5 
npm install n8n@2.31.5
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls n8n

How to Check if You Are Affected

To determine whether your Node.js application is affected by GHSA-hx4h-vr3m-45vh, inspect your project dependencies using npm:

npm ls n8n

Analyze the terminal output to locate any version of n8n in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.123.67), your application is affected.

Note: The npm ls n8n command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), where the product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. In n8n, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Impact An authenticated user able to create or edit a workflow expression could abuse the expression engine's array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process, leading to a denial of service. Both self-hosted and cloud instances running the VM expression engine are affected. ## Patches The issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. 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. - Disable the VM expression engine if an alternative is available for your deployment. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

GHSA-hx4h-vr3m-45vh Affected n8n Versions

3 component(s)
Fixed Versions:
1.123.672.32.12.31.5
Product / Package Ecosystem Affected Versions Fixed Version
n8n
npm/n8n
npm
< 1.123.67
1.123.67
n8n
npm/n8n
npm
≥ 2.32.0
< 2.32.1
2.32.1
n8n
npm/n8n
npm
≥ 2.0.0-rc.0
< 2.31.5
2.31.5

References

GitHub Advisory / Wiki ADVISORY
https://github.com/n8n-io/n8n/security/advisories/GHSA-hx4h-vr3m-45vh
Security Fix Commit FIX COMMIT
https://github.com/n8n-io/n8n/commit/f69dfc6dd2178a14ea1624d2e1d403c2e755042f
n8n Source Repository REPOSITORY
https://github.com/n8n-io/n8n
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.67
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n@2.31.5
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n@2.32.1

Frequently Asked Questions

What is GHSA-hx4h-vr3m-45vh?
GHSA-hx4h-vr3m-45vh is a security vulnerability in n8n involving Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which n8n versions are affected?
Affected versions include releases prior to 1.123.67, 2.32.1, 2.31.5 across affected packages: n8n.
What version fixes GHSA-hx4h-vr3m-45vh?
Upgrading to 1.123.67, 2.32.1, 2.31.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is n8n affected?
Yes, n8n is affected in releases prior to 1.123.67, 2.32.1, 2.31.5. Upgrade your dependency to 1.123.67, 2.32.1, 2.31.5 or later.
What CWE is associated with GHSA-hx4h-vr3m-45vh?
GHSA-hx4h-vr3m-45vh is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.).
How can I check npm dependencies for GHSA-hx4h-vr3m-45vh?
Run the dependency tree command: 'npm ls n8n'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hx4h-vr3m-45vh",
  "modified" : "2026-07-22T22:13:04Z",
  "published" : "2026-07-22T22:13:04Z",
  "aliases" : [ ],
  "summary" : "n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service",
  "details" : "## Impact\n\nAn authenticated user able to create or edit a workflow expression could abuse the expression engine's array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process, leading to a denial of service.\n\nBoth self-hosted and cloud instances running the VM expression engine are affected.\n\n## Patches\n\nThe issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability.\n\n## Workarounds\n\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Restrict n8n instance access to fully trusted users only.\n- Disable the VM expression engine if an alternative is available for your deployment.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
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      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.123.67"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
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    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
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      }, {
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    } ]
  }, {
    "package" : {
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    "ranges" : [ {
      "type" : "ECOSYSTEM",
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      }, {
        "fixed" : "2.31.5"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/security/advisories/GHSA-hx4h-vr3m-45vh"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/commit/f69dfc6dd2178a14ea1624d2e1d403c2e755042f"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/n8n-io/n8n"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.67"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/releases/tag/n8n@2.31.5"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/releases/tag/n8n@2.32.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-22T22:13:04Z",
    "nvd_published_at" : null
  }
}