CVE-2026-59206: n8n Prototype Pollution Vulnerability

HIGH
Advisory Identifier: GHSA-75qm-gp28-rcq9
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CWE-1321
Published
Advisory Summary

CVE-2026-59206 is a HIGH prototype pollution 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 workflow credentials leads to unauthenticated user and project enumeration. Remediation is available by upgrading affected packages to version 1.123.61, 2.28.1, 2.27.4.

CVE-2026-59206 at a Glance

CVE Identifier CVE-2026-59206
GHSA Identifier GHSA-75qm-gp28-rcq9
Severity HIGH
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 CVE-2026-59206

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: 1.123.61 
npm install n8n@1.123.61
n8n fixed: 2.28.1 
npm install n8n@2.28.1
n8n fixed: 2.27.4 
npm install n8n@2.27.4
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 CVE-2026-59206, 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 1.123.61), 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 with the default `workflow:create` permission could pollute `Object.prototype` through a crafted workflow saved, updated, or imported via the workflow API. This can be leveraged to bypass authentication, allowing unauthenticated requests to be treated as a privileged user and exposing endpoints such as the user and project listings. As a result, every account's personal data (email, role, MFA status) and all projects on the instance may be disclosed to unauthenticated callers. The pollution can also corrupt global state, making parts of the instance unresponsive until restarted. ## Patches The issue has been fixed in n8n versions 1.123.61, 2.27.4, and 2.28.1. 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 workflow creation and editing permissions to fully trusted users only. - Restrict network access to the n8n instance to trusted users only. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

CVE-2026-59206 Affected n8n Versions

3 component(s)
Fixed Versions:
1.123.612.28.12.27.4
Product / Package Ecosystem Affected Versions Fixed Version
n8n
npm/n8n
npm
< 1.123.61
1.123.61
n8n
npm/n8n
npm
≥ 2.28.0
< 2.28.1
2.28.1
n8n
npm/n8n
npm
≥ 2.0.0-rc.0
< 2.27.4
2.27.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/n8n-io/n8n/security/advisories/GHSA-75qm-gp28-rcq9
NVD — CVE-2026-59206 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59206
n8n Source Repository REPOSITORY
https://github.com/n8n-io/n8n
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n%402.27.4
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n%402.28.1

Frequently Asked Questions

What is CVE-2026-59206?
CVE-2026-59206 is a security vulnerability in n8n involving Prototype Pollution via Workflow Credentials Leads to Unauthenticated User and Project Enumeration under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which n8n versions are affected?
Affected versions include releases prior to 1.123.61, 2.28.1, 2.27.4 across affected packages: n8n.
What version fixes CVE-2026-59206?
Upgrading to 1.123.61, 2.28.1, 2.27.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is n8n affected?
Yes, n8n is affected in releases prior to 1.123.61, 2.28.1, 2.27.4. Upgrade your dependency to 1.123.61, 2.28.1, 2.27.4 or later.
What CWE is associated with CVE-2026-59206?
CVE-2026-59206 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 CVE-2026-59206?
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-75qm-gp28-rcq9",
  "modified" : "2026-07-22T21:57:21Z",
  "published" : "2026-07-22T21:57:21Z",
  "aliases" : [ "CVE-2026-59206" ],
  "summary" : "n8n: Prototype Pollution via Workflow Credentials Leads to Unauthenticated User and Project Enumeration",
  "details" : "## Impact\nAn authenticated user with the default `workflow:create` permission could pollute `Object.prototype` through a crafted workflow saved, updated, or imported via the workflow API. This can be leveraged to bypass authentication, allowing unauthenticated requests to be treated as a privileged user and exposing endpoints such as the user and project listings. As a result, every account's personal data (email, role, MFA status) and all projects on the instance may be disclosed to unauthenticated callers. The pollution can also corrupt global state, making parts of the instance unresponsive until restarted.\n\n## Patches\nThe issue has been fixed in n8n versions 1.123.61, 2.27.4, and 2.28.1. Users should upgrade to one of these versions or later to remediate the vulnerability.\n\n## Workarounds\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Restrict workflow creation and editing permissions to fully trusted users only.\n- Restrict network access to the n8n instance to trusted users only.\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:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.123.61"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.28.0"
      }, {
        "fixed" : "2.28.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0-rc.0"
      }, {
        "fixed" : "2.27.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/security/advisories/GHSA-75qm-gp28-rcq9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-59206"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/n8n-io/n8n"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/releases/tag/n8n%402.27.4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/releases/tag/n8n%402.28.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-22T21:57:21Z",
    "nvd_published_at" : "2026-07-09T16:16:46Z"
  }
}