{"id":"CVE-2026-54309","aliases":["GHSA-qrx8-25qr-5r7v"],"url":"https://o3.security/vulnerability/CVE-2026-54309","summary":"n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions","details":"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.","published":"2026-06-23T15:36:13.270Z","modified":"2026-08-07T11:31:08.979950183Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"n8n","fixedVersion":"2.26.2"},{"ecosystem":"npm","name":"n8n","fixedVersion":"2.25.7"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54309.json"},{"type":"ADVISORY","url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54309"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:08.979950183Z"}}