{"id":"GHSA-qrx8-25qr-5r7v","revision":"3c27b47e43214819a202d7cfbb4ed64e","records":[{"revision":"3c27b47e43214819a202d7cfbb4ed64e","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-qrx8-25qr-5r7v","aliases":["CVE-2026-54309"],"title":"n8n: MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions","description":"## Impact\nWhen `@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.\n\nWhere 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.\n\nThis issue only affects instances where `@n8n/mcp-browser` is run with the HTTP transport (`--transport http`). The default transport is stdio, which is not affected.\n\n## Patches\nThe issue has been fixed in n8n versions 2.25.7, and 2.26.2. Users should upgrade to one of these versions or later to remediate the vulnerability.\n\n## Workarounds\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Avoid running `@n8n/mcp-browser` with the HTTP transport; use the default stdio transport instead.\n- If HTTP transport is required, restrict network access to the listening port to trusted clients only using host-based firewall rules.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.","state":0,"publishedAt":"2026-06-16T23:32:31+00:00","modifiedAt":"2026-07-20T13:45:32.2359494+00:00","affected":[{"ecosystem":"npm","name":"n8n","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"2.26.0"},{"kind":"fixed","version":"2.26.2"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"npm","name":"n8n","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"2.25.7"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L","score":null,"severity":null},{"system":"CVSS_V4","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","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v","https://nvd.nist.gov/vuln/detail/CVE-2026-54309","https://github.com/n8n-io/n8n"],"sourceUrl":"https://github.com/advisories/GHSA-qrx8-25qr-5r7v","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-qrx8-25qr-5r7v","identifiers":["GHSA-qrx8-25qr-5r7v","CVE-2026-54309"]},"retained":false,"historicalAffected":[]}],"coverage":[]}