CVE-2026-54309: 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…

PriorityP266critical10CVSS 3.1

AVNACLPRNUINSCCHIHAL

EPSS

0.40%

32.2th percentile

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.

Affected

6 ranges

Vendor	Product	Version range	Fixed in
n8n-io	n8n	< 2.25.7	2.25.7
n8n-io	n8n	—	—
n8n	n8n	< 2.25.7	2.25.7
n8n	n8n	>= 0 < 2.25.7	2.25.7
n8n	n8n	>= 2.26.0 < 2.26.2	2.26.2
n8n	n8n	>= 2.26.0 < 2.26.2	2.26.2

CVSS provenance

nvdv3.110.0CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

nvdv4.08.8HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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