CVE-2026-54309Network attack vector

Browser-profile control via unauthenticated MCP sessions

Published Jun 23, 2026 · Updated Jun 23, 2026

Missing authentication in n8n before 2.25.7 and 2.26.0 through 2.26.1 allows remote attackers to invoke browser-control tools. The @n8n/mcp-browser HTTP endpoint accepts session initialization and tool calls without verifying credentials, exposing navigation, JavaScript evaluation, cookies, and storage in an attached browser profile. Exploitation requires the non-default HTTP transport, an installed AI Browser Bridge extension, and an active browser connection; the default stdio transport is unaffected.

CVSS severity8.8
High
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in n8n before 2.25.7 and 2.26.0 through 2.26.1 allows remote attackers to invoke browser-control tools. The @n8n/mcp-browser HTTP endpoint accepts session initialization and tool calls without verifying credentials, exposing navigation, JavaScript evaluation, cookies, and storage in an attached browser profile. Exploitation requires the non-default HTTP transport, an installed AI Browser Bridge extension, and an active browser connection; the default stdio transport is unaffected.

The record

CVE
CVE-2026-54309
Published
Jun 23, 2026
Updated
Jun 23, 2026
Vendor
n8n
Product
n8n
Classifications
CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.25.7
  2. Affected versionversion=>= 2.26.0, < 2.26.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

n8n · n8nversion=< 2.25.7; version=>= 2.26.0, < 2.26.2

Published CVSS scores

10.0NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
8.8GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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