CVE-2026-33749
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 · uneditedn8n is an open source workflow automation platform. Prior to versions 1.123.27, 2.13.3, and 2.14.1, 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. 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. If upgrading is not immediately possible, administrators should consider the following temporary mitigations: Limit workflow creation and editing permissions to fully trusted users only, and/or 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.
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 confidenceAuthenticated stored XSS vulnerability in n8n workflow automation platform where users with workflow creation/modification permissions can craft workflows producing HTML binary data objects without filenames. The /rest/binary-data endpoint serves these inline without Content-Disposition or CSP headers, allowing the HTML to execute JavaScript in the victim's browser with full same-origin access.
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< 1.123.27>= 2.0.0, < 2.13.3= 2.14.0CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
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 checksWork through these to decide whether this CVE applies to you.
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Determine n8n versionRun `n8n --version` from the command line, or check the package.json file in the n8n installation directory, or access the n8n UI and look for the version in the footer of any pageAffected if The installed version is < 1.123.27, or >= 2.0.0 and < 2.13.3, or exactly 2.14.0
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Identify users with workflow permissionsAccess n8n admin settings and review user roles and permissions. Look for any users assigned roles that include workflow creation or modification privilegesAffected if There are users other than fully trusted administrators with workflow creation or modification permissions
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Verify /rest/binary-data endpoint accessibilityAttempt a HEAD or GET request to the /rest/binary-data endpoint from an authenticated session using curl or a similar tool: `curl -I -u <user>:<password> https://<n8n-host>/rest/binary-data`Affected if The endpoint returns a 200 OK response and serves content without Content-Disposition header
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Check response headers for CSP protectionMake an authenticated request to /rest/binary-data and inspect response headers for Content-Security-Policy and Content-Disposition headersAffected if The response lacks a Content-Security-Policy header and lacks a Content-Disposition: attachment header for binary data
You are affected if running an affected n8n version AND having users with workflow creation/modification permissions AND the /rest/binary-data endpoint serves content inline without protective headers.
Generated from the published advisory. Verify against your own configuration.
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 · scoped1.123.272.13.3
Upgrade immediately to n8n versions 1.123.27, 2.13.3, or 2.14.1 or later. As temporary mitigation, strictly limit workflow creation/editing permissions to trusted users only and restrict network access to the n8n instance.
Upgrade to n8n version 1.123.27 (for 1.x users), 2.13.3, or 2.14.1 or later (for 2.x users)
- 1. Identify the current n8n version by checking the n8n UI footer or running `n8n --version` in the CLI
- 2. If running version 1.x (< 1.123.27), plan upgrade to version 1.123.27 or later
- 3. If running version 2.x (>= 2.0.0 and < 2.13.3, or exactly 2.14.0), plan upgrade to version 2.13.3 or 2.14.1 or later
- 4. Back up the n8n database and configuration files before upgrading
- 5. For Docker deployments: Update the image tag in docker-compose.yml or your container orchestration to the target version (e.g., `image: n8nio/n8n:1.123.27` or `image: n8nio/n8n:2.14.1`)
- 6. For npm installations: Run `npm install -g n8n@<target-version>` or `n8n update`
- 7. Restart the n8n service to apply the new version
- 8. Verify the upgrade by checking the version in the UI and confirming the `/rest/binary-data` endpoint now properly sets Content-Disposition and Content-Security-Policy headers
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-33749 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-33749 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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