Vulnerability · Published Jun 23, 2026 · Assigned by GitHub_M
CVE-2026-54309n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
High 8.8
In plain English
A high-severity missing authentication in n8n from n8n-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | n8n | 2.26.2 | GHSA-qrx8-25qr-5r7v |
| npm | n8n | 2.25.7 | GHSA-qrx8-25qr-5r7v |
Affected products (as reported)
Weakness: CWE-306 · 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
References
- https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v x_refsource_CONFIRM