CVE-2026-54309

high

Description

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.

References

https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v

Details

Source: Mitre, NVD

Published: 2026-06-23

Updated: 2026-06-25

Risk Information

CVSS v2

Base Score: 9.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:P

Severity: High

CVSS v3

Base Score: 10

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

Severity: Critical

CVSS v4

Base Score: 8.8

Vector: 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