{"id":"CVE-2026-54309","state":"PUBLISHED","title":"n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions","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.","publishedAt":"2026-06-23T15:36:13.270Z","updatedAt":"2026-06-23T15:45:15.836Z","severity":{"score":8.8,"label":"High","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["n8n-io n8n"],"affected":[{"vendor":"n8n-io","product":"n8n","versions":[{"version":">= 2.26.0, < 2.26.2","status":"affected"},{"version":"< 2.25.7","status":"affected"}]}],"references":["https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v"],"weaknesses":["CWE-306"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/54xxx/CVE-2026-54309.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-54309","state":"PUBLISHED","datePublished":"2026-06-23T15:36:13.270Z","dateUpdated":"2026-06-23T15:45:15.836Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-12T18:42:02.222Z"},"containers":{"cna":{"title":"n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions","descriptions":[{"lang":"en","value":"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":[{"vendor":"n8n-io","product":"n8n","versions":[{"version":">= 2.26.0, < 2.26.2","status":"affected"},{"version":"< 2.25.7","status":"affected"}]}],"references":[{"url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v","name":"https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.8,"baseSeverity":"HIGH","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-306","lang":"en","description":"CWE-306: Missing Authentication for Critical Function","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-06-23T15:36:13.270Z"},"source":{"advisory":"GHSA-qrx8-25qr-5r7v","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-23T15:45:10.329452Z","id":"CVE-2026-54309","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-23T15:45:15.836Z"}}]}}}