CVE-2026-54309 json
n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
published 2026-06-16 4 mo ago modified 2026-10-26 14 d ago also GHSA-qrx8-25qr-5r7v , EUVD-2026-38468
- cvss
- 10.0
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 46%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm n8n 2.25.7, 2.26.2
- n8n n8n 2.25.7, 2.26.2
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.8 | 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 |
| CNA | 4.0 | 8.8 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L |
| GitHub | 3.1 | 10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | n8n | >=2.26.0, <2.26.2 <2.25.7 |
2.26.2 2.25.7 |
Affected products
- n8n-io n8n
Classification
- Weakness
-
- CWE-306 Missing Authentication for Critical Functionality
References
-
github.com
/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v
web, mitigation, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-54309
advisory
-
github.com
/n8n-io/n8n
package
Sources
- CVE List CVE-2026-54309
- GitHub Advisory GHSA-qrx8-25qr-5r7v
- NVD CVE-2026-54309
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.