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N8nApplication

CVE-2026-56356

MEDIUM · 5.4 CVSS v3.1 Published 2026-06-30
Fix available
A fix is available. Upgrade to 1.123.27 / 2.13.3 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
n8n contains a stored cross-site scripting vulnerability in the Chat Trigger node's Custom CSS field due to a misconfiguration of the sanitize-html library. Affected releases are those before 1.123.27, the 2.0.0 through 2.13.2 line, and 2.14.0 (fixed in 1.123.27, 2.13.3, and 2.14.1). An authenticated user with permission to create or modify workflows can inject JavaScript that bypasses sanitization, resulting in stored XSS against any user who visits the public chat page.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

n8n contains a stored cross-site scripting vulnerability in the Chat Trigger node's Custom CSS field. The sanitize-html library is misconfigured, allowing authenticated users with workflow creation/modification permissions to inject malicious JavaScript that bypasses sanitization. This payload executes against any user who visits the affected public chat page.

MitigationUpgrade to n8n versions 1.123.27, 2.13.3, or 2.14.1 or later to receive the patched sanitize-html configuration. Review existing workflows for any malicious Custom CSS entries.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
N8nApplication
Affected:< 1.123.27>= 2.0.0, < 2.13.3= 2.14.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed n8n version
    Run `n8n --version` from the command line, or log into the n8n web interface and navigate to Settings > About to view the version number.
    Affected if The version is less than 1.123.27, or between 2.0.0 and 2.13.3 inclusive, or exactly 2.14.0.
  2. Identify workflows using Chat Trigger nodes
    Export all workflows or query the database for workflows containing a node with type 'n8n-nodes-base.chatTrigger' or 'chatTrigger'. Each workflow JSON will contain a 'nodes' array - inspect each for a node with name or type containing 'chat' or 'Chat' that has a Custom CSS field.
    Affected if Any workflow contains a Chat Trigger node with a non-empty Custom CSS field.
  3. Inspect Custom CSS content in Chat Trigger nodes
    For each Chat Trigger node found, examine the node parameters for a field named 'customCss' or 'css'. Review the CSS content for any suspicious patterns such as JavaScript event handlers (onclick, onload, onerror), javascript: URLs, or HTML-like markup that may have bypassed sanitization.
    Affected if The Custom CSS field contains any JavaScript event handlers, javascript: protocols, or HTML tags that were not stripped by sanitization.
  4. Determine if affected Chat Trigger workflows are active
    Check the workflow status in n8n. Active Chat Trigger workflows expose a public webhook URL (typically under /webhook/ or /chat/ path). Verify which workflow IDs are enabled by checking the 'active' flag in workflow settings or the UI toggle.
    Affected if A workflow with a vulnerable Chat Trigger configuration is set to active and its webhook URL is publicly accessible.

You are affected if your n8n version falls within the vulnerable ranges AND you have an active workflow containing a Chat Trigger node with a populated Custom CSS field that contains unsanitized JavaScript or HTML.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.123.27 / 2.13.3 or later
Fixed in 1.123.272.13.3
Interim mitigation

Upgrade to n8n versions 1.123.27, 2.13.3, or 2.14.1 or later to receive the patched sanitize-html configuration. Review existing workflows for any malicious Custom CSS entries.

Recommended fix High confidence

1.123.27 (for 1.x branch), 2.13.3 (for 2.0.0-2.13.x branch), or 2.14.1 (for 2.14.x branch)

  1. Identify the current n8n version running in your environment
  2. If running version 1.x (< 1.123.27): upgrade to version 1.123.27 or later
  3. If running version 2.0.0 through 2.13.2: upgrade to version 2.13.3 or later
  4. If running version 2.14.0: upgrade to version 2.14.1 or later
  5. After upgrade, verify the Chat Trigger node's Custom CSS field sanitization is working correctly

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in N8n Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-56356 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data