CVE-2026-86075: n8n Unauthenticated Persistent Storage Exhaustion Vulnerability

HIGH
Advisory Identifier: GHSA-hh89-3r9w-qj3j
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CWE-770
Published
Advisory Summary

CVE-2026-86075 is a HIGH unauthenticated persistent storage exhaustion vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting n8n libraries in the npm ecosystem. The issue involves unauthenticated persistent storage exhaustion via oauth dynamic client registration endpoint. Remediation is available by upgrading affected packages to version 2.38.2, 2.37.7.

CVE-2026-86075 at a Glance

CVE Identifier CVE-2026-86075
GHSA Identifier GHSA-hh89-3r9w-qj3j
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product n8n
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-86075

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: 2.38.2 
npm install n8n@2.38.2
n8n fixed: 2.37.7 
npm install n8n@2.37.7
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-2026-86075, 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 2.38.2), 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-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. 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 The OAuth Dynamic Client Registration endpoints validated field sizes only for `redirect_uris`, leaving `client_name` and `grant_types` bounded by presence checks alone. An unauthenticated remote caller could submit arbitrarily large values in either field and have them persisted to the database. Repeated registration therefore grew persistent storage without limit and without any account on the instance. The patch caps `client_name` at its column length and limits `grant_types` to the grant types the server actually implements, with the array capped at that count. ## Patches The issue has been fixed in n8n versions 2.37.7 and 2.38.2. 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 network access to the n8n instance so that only trusted clients can reach it. - Place the instance behind a reverse proxy configured to enforce strict request body size limits below the default 16 MiB. - Monitor database size for unexpected growth and audit the `oauth_clients` table for anomalous entries. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

CVE-2026-86075 Affected n8n Versions

2 component(s)
Fixed Versions:
2.38.22.37.7
Product / Package Ecosystem Affected Versions Fixed Version
n8n
npm/n8n
npm
≥ 2.38.0
< 2.38.2
2.38.2
n8n
npm/n8n
npm
< 2.37.7
2.37.7

References

GitHub Advisory / Wiki ADVISORY
https://github.com/n8n-io/n8n/security/advisories/GHSA-hh89-3r9w-qj3j
NVD — CVE-2026-86075 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86075
n8n Source Repository REPOSITORY
https://github.com/n8n-io/n8n
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2

Frequently Asked Questions

What is CVE-2026-86075?
CVE-2026-86075 is a security vulnerability in n8n involving Unauthenticated Persistent Storage Exhaustion via OAuth Dynamic Client Registration Endpoint under CWE-770: Allocation of Resources Without Limits or Throttling.
Which n8n versions are affected?
Affected versions include releases prior to 2.38.2, 2.37.7 across affected packages: n8n.
What version fixes CVE-2026-86075?
Upgrading to 2.38.2, 2.37.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is n8n affected?
Yes, n8n is affected in releases prior to 2.38.2, 2.37.7. Upgrade your dependency to 2.38.2, 2.37.7 or later.
What CWE is associated with CVE-2026-86075?
CVE-2026-86075 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check npm dependencies for CVE-2026-86075?
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-hh89-3r9w-qj3j",
  "modified" : "2026-09-10T15:11:31Z",
  "published" : "2026-09-10T15:11:31Z",
  "aliases" : [ "CVE-2026-86075" ],
  "summary" : "n8n: Unauthenticated Persistent Storage Exhaustion via OAuth Dynamic Client Registration Endpoint",
  "details" : "## Impact\n\nThe OAuth Dynamic Client Registration endpoints validated field sizes only for `redirect_uris`, leaving `client_name` and `grant_types` bounded by presence checks alone. An unauthenticated remote caller could submit arbitrarily large values in either field and have them persisted to the database. Repeated registration therefore grew persistent storage without limit and without any account on the instance.  The patch caps `client_name` at its column length and limits `grant_types` to the grant types the server actually implements, with the array capped at that count.\n\n## Patches\n\nThe issue has been fixed in n8n versions 2.37.7 and 2.38.2. 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 network access to the n8n instance so that only trusted clients can reach it.\n- Place the instance behind a reverse proxy configured to enforce strict request body size limits below the default 16 MiB.\n- Monitor database size for unexpected growth and audit the `oauth_clients` table for anomalous entries.\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:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.38.0"
      }, {
        "fixed" : "2.38.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.37.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/security/advisories/GHSA-hh89-3r9w-qj3j"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-86075"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/n8n-io/n8n"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-10T15:11:31Z",
    "nvd_published_at" : "2026-09-08T22:19:16Z"
  }
}