CVE-2026-33749: N8n Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-qfc3-hm4j-7q77
Share
CVSS 8.9
CWE-79
Published
Advisory Summary

CVE-2026-33749 is a MODERATE (CVSS 8.9) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting N8n libraries in the npm ecosystem. The issue involves n8n vulnerable to xss via binary data inline html rendering. Remediation is available by upgrading affected packages to version 1.123.27, 2.14.1, 2.13.3.

CVE-2026-33749 at a Glance

CVE Identifier CVE-2026-33749
GHSA Identifier GHSA-qfc3-hm4j-7q77
Severity MODERATE
CVSS v3.1 Base Score 8.9
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product N8n
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 8.9

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

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability Low (A:L)

How to Fix CVE-2026-33749

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: 1.123.27 
npm install n8n@1.123.27
n8n fixed: 2.14.1 
npm install n8n@2.14.1
n8n fixed: 2.13.3 
npm install n8n@2.13.3
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-2026-33749, 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 1.123.27), 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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. 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 permission to create or modify workflows could craft a workflow that produces an HTML binary data object without a filename. The `/rest/binary-data` endpoint served such responses inline on the n8n origin without `Content-Disposition` or `Content-Security-Policy` headers, allowing the HTML to render in the browser with full same-origin JavaScript access. By sending the resulting URL to a higher-privileged user, an attacker could execute JavaScript in the victim's authenticated session, enabling exfiltration of workflows and credentials, modification of workflows, or privilege escalation to admin. ## Patches The issue has been fixed in n8n versions 1.123.27, 2.13.3, and 2.14.1. 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: - Limit workflow creation and editing permissions to fully trusted users only. - Restrict network access to the n8n instance to prevent untrusted users from accessing binary data URLs. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

CVE-2026-33749 Affected N8n Versions

3 component(s)
Fixed Versions:
1.123.272.14.12.13.3
Product / Package Ecosystem Affected Versions Fixed Version
n8n
npm/n8n
npm
< 1.123.27
1.123.27
n8n
npm/n8n
npm
≥ 2.14.0
< 2.14.1
All 1 versions
2.14.0
2.14.1
n8n
npm/n8n
npm
≥ 2.0.0-rc.0
< 2.13.3
2.13.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/n8n-io/n8n/security/advisories/GHSA-qfc3-hm4j-7q77
NVD — CVE-2026-33749 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33749
N8n Source Repository REPOSITORY
https://github.com/n8n-io/n8n

Frequently Asked Questions

What is CVE-2026-33749?
CVE-2026-33749 is a security vulnerability in N8n involving n8n Vulnerable to XSS via Binary Data Inline HTML Rendering under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which N8n versions are affected?
Affected versions include releases prior to 1.123.27, 2.14.1, 2.13.3 across affected packages: n8n.
What version fixes CVE-2026-33749?
Upgrading to 1.123.27, 2.14.1, 2.13.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is n8n affected?
Yes, n8n is affected in releases prior to 1.123.27, 2.14.1, 2.13.3. Upgrade your dependency to 1.123.27, 2.14.1, 2.13.3 or later.
What is the CVSS score of CVE-2026-33749?
CVE-2026-33749 has a CVSS v3.1 base score of 8.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L.
What CWE is associated with CVE-2026-33749?
CVE-2026-33749 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check npm dependencies for CVE-2026-33749?
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-qfc3-hm4j-7q77",
  "modified" : "2026-03-26T18:28:44Z",
  "published" : "2026-03-26T18:28:44Z",
  "aliases" : [ "CVE-2026-33749" ],
  "summary" : "n8n Vulnerable to XSS via Binary Data Inline HTML Rendering",
  "details" : "## Impact\nAn authenticated user with permission to create or modify workflows could craft a workflow that produces an HTML binary data object without a filename. The `/rest/binary-data` endpoint served such responses inline on the n8n origin without `Content-Disposition` or `Content-Security-Policy` headers, allowing the HTML to render in the browser with full same-origin JavaScript access.\n\nBy sending the resulting URL to a higher-privileged user, an attacker could execute JavaScript in the victim's authenticated session, enabling exfiltration of workflows and credentials, modification of workflows, or privilege escalation to admin.\n\n## Patches\nThe issue has been fixed in n8n versions 1.123.27, 2.13.3, and 2.14.1. 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- Limit workflow creation and editing permissions to fully trusted users only.\n- Restrict network access to the n8n instance to prevent untrusted users from accessing binary data URLs.\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:L/PR:L/UI:R/S:C/C:H/I:H/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:H/SI:H/SA:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.123.27"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.14.0"
      }, {
        "fixed" : "2.14.1"
      } ]
    } ],
    "versions" : [ "2.14.0" ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0-rc.0"
      }, {
        "fixed" : "2.13.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/security/advisories/GHSA-qfc3-hm4j-7q77"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33749"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/n8n-io/n8n"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-26T18:28:44Z",
    "nvd_published_at" : "2026-03-25T19:16:51Z"
  }
}