CVE-2026-33720: N8n N8n Has Authorization Bypass Vulnerability

MODERATE
Advisory Identifier: GHSA-vpgc-2f6g-7w7x
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CVSS 4.7
CWE-863
Published
Advisory Summary

CVE-2026-33720 is a MODERATE (CVSS 4.7) n8n has authorization bypass vulnerability (CWE-863: Incorrect Authorization) affecting N8n libraries in the npm ecosystem. The issue involves n8n has authorization bypass in oauth callback via n8n_skip_auth_on_oauth_callback. Remediation is available by upgrading affected packages to version 2.8.0.

CVE-2026-33720 at a Glance

CVE Identifier CVE-2026-33720
GHSA Identifier GHSA-vpgc-2f6g-7w7x
Severity MODERATE
CVSS v3.1 Base Score 4.7
CWE Classification CWE-863: Incorrect Authorization
Affected Product N8n
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 4.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-33720

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: 2.8.0 
npm install n8n@2.8.0
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-2026-33720, 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 2.8.0), 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-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. 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 When the `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK` environment variable is set to `true`, the OAuth callback handler skips ownership verification of the OAuth state parameter. This allows an attacker to trick a victim into completing an OAuth flow against a credential object the attacker controls, causing the victim's OAuth tokens to be stored in the attacker's credential. The attacker can then use those tokens to execute workflows in their name. - This issue only affects instances where `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true` is explicitly configured (non-default). ## Patches The issue has been fixed in n8n version 2.8.0. Users should upgrade to this version or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Avoid enabling `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true` unless strictly required. - Restrict access to the n8n instance to fully trusted users only. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

CVE-2026-33720 Affected N8n Versions

1 component(s)
Fixed Versions:
2.8.0
Product / Package Ecosystem Affected Versions Fixed Version
n8n
npm/n8n
npm
< 2.8.0
2.8.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/n8n-io/n8n/security/advisories/GHSA-vpgc-2f6g-7w7x
NVD — CVE-2026-33720 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33720
N8n Source Repository REPOSITORY
https://github.com/n8n-io/n8n

Frequently Asked Questions

What is CVE-2026-33720?
CVE-2026-33720 is a security vulnerability in N8n involving n8n Has Authorization Bypass in OAuth Callback via N8N_SKIP_AUTH_ON_OAUTH_CALLBACK under CWE-863: Incorrect Authorization.
Which N8n versions are affected?
Affected versions include releases prior to 2.8.0 across affected packages: n8n.
What version fixes CVE-2026-33720?
Upgrading to 2.8.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is n8n affected?
Yes, n8n is affected in releases prior to 2.8.0. Upgrade your dependency to 2.8.0 or later.
What is the CVSS score of CVE-2026-33720?
CVE-2026-33720 has a CVSS v3.1 base score of 4.7 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2026-33720?
CVE-2026-33720 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check npm dependencies for CVE-2026-33720?
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-vpgc-2f6g-7w7x",
  "modified" : "2026-03-25T21:57:55Z",
  "published" : "2026-03-25T21:57:55Z",
  "aliases" : [ "CVE-2026-33720" ],
  "summary" : "n8n Has Authorization Bypass in OAuth Callback via N8N_SKIP_AUTH_ON_OAUTH_CALLBACK",
  "details" : "## Impact\nWhen the `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK` environment variable is set to `true`, the OAuth callback handler skips ownership verification of the OAuth state parameter. This allows an attacker to trick a victim into completing an OAuth flow against a credential object the attacker controls, causing the victim's OAuth tokens to be stored in the attacker's credential. The attacker can then use those tokens to execute workflows in their name.\n\n- This issue only affects instances where `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true` is explicitly configured (non-default).\n\n## Patches\nThe issue has been fixed in n8n version 2.8.0. Users should upgrade to this version or later to remediate the vulnerability.\n\n## Workarounds\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Avoid enabling `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true` unless strictly required.\n- Restrict access to the n8n instance to fully 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_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.8.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/security/advisories/GHSA-vpgc-2f6g-7w7x"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33720"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/n8n-io/n8n"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-25T21:57:55Z",
    "nvd_published_at" : "2026-03-25T19:16:50Z"
  }
}