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N8nApplication

CVE-2026-54309

CRITICAL · 10.0 CVSS v3.1 Published 2026-06-23
Fix available
A fix is available. Upgrade to 2.25.7 / 2.26.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, when @n8n/mcp-browser is run in HTTP transport mode, the MCP endpoint accepts session initialization and tool invocation requests without any authentication. Any network-reachable client, or any website visited by the user, can establish an MCP session and invoke browser-control tools. Where the n8n AI Browser Bridge extension is installed and a browser connection is active, an unauthenticated caller can access browser-control capabilities including navigation, JavaScript evaluation, and cookie and storage access against the user's real browser profile. This issue only affects instances where @n8n/mcp-browser is run with the HTTP transport (--transport http). This vulnerability is fixed in 2.25.7 and 2.26.2.

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

The @n8n/mcp-browser component when run in HTTP transport mode (--transport http) lacks authentication on its MCP endpoint, allowing any network-reachable client or website to establish MCP sessions and invoke browser-control tools. When the n8n AI Browser Bridge extension is installed with an active browser connection, unauthenticated attackers can navigate, execute JavaScript, and access cookies/storage against the user's real browser profile.

MitigationUpdate to version 2.25.7 or 2.26.2 immediately and avoid using HTTP transport mode until patched. If HTTP transport is required, implement network-level access controls to restrict exposure.

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:< 2.25.7>= 2.26.0, < 2.26.2

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
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
Low

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

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. Determine installed n8n version
    Run 'n8n --version' or check package.json for the n8n version number
    Affected if version is below 2.25.7, OR between 2.26.0 and 2.26.1 inclusive
  2. Identify if @n8n/mcp-browser is in use
    Search configuration files (workflows, settings, or environment) for references to '@n8n/mcp-browser' or 'mcp-browser'
    Affected if the mcp-browser component is present in the configuration
  3. Confirm HTTP transport mode is enabled
    Search for '--transport http' flag or 'transport: http' in n8n settings, environment variables, or startup configuration
    Affected if the HTTP transport mode is explicitly enabled for the mcp-browser component
  4. Check if AI Browser Bridge extension is active
    Inspect browser extensions in the browser profile (chrome://extensions for Chrome/Edge, about:addons for Firefox) for the 'n8n AI Browser Bridge' extension
    Affected if the n8n AI Browser Bridge extension is installed and enabled in the user's browser

You are affected if n8n version falls in the vulnerable range, the mcp-browser component uses HTTP transport mode, and the n8n AI Browser Bridge extension is active in your browser profile.

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 2.25.7 / 2.26.2 or later
Fixed in 2.25.72.26.2
Interim mitigation

Update to version 2.25.7 or 2.26.2 immediately and avoid using HTTP transport mode until patched. If HTTP transport is required, implement network-level access controls to restrict exposure.

Recommended fix High confidence

2.25.7 or 2.26.2 (depending on current version branch)

  1. Identify the current n8n version in use by checking the package.json or running the version command
  2. Determine which version line you are on (2.25.x or 2.26.x)
  3. If on 2.25.x line, upgrade to version 2.25.7 or later
  4. If on 2.26.x line, upgrade to version 2.26.2 or later
  5. After upgrade, verify that @n8n/mcp-browser is running the corrected version
  6. If HTTP transport mode (--transport http) is still required, confirm the vulnerability is patched by testing that authentication is now required for MCP endpoint access

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

Fix this in N8n Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,620
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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-2026-54309 in production — separate from our analysis above.

No notes yet

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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