CVE-2026-54309
n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
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.
- Record
CVE-2026-54309- CVSS 4.0
- 8.8 High
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 - Weakness
- CWE-306
- Updated
- 2026-11-02
EUVDEUVD-2026-38468
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.
- Record
EUVD-2026-38468- CVSS 4.0
- 8.8 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-qrx8-25qr-5r7v
n8n: MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
Impact
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). The default transport is stdio, which is not affected.
Patches
The 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.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Avoid running
@n8n/mcp-browserwith the HTTP transport; use the default stdio transport instead. - If HTTP transport is required, restrict network access to the listening port to trusted clients only using host-based firewall rules.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
- Record
GHSA-qrx8-25qr-5r7v- CVSS 4.0
- 8.8 High
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 - CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L - Weakness
- CWE-306
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-54309- CVSS 4.0
- 8.8 High
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 - CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L - Weakness
- CWE-306
- Updated
- 2026-11-02
OSV
n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
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.
- Record
CVE-2026-54309- CVSS 4.0
- 8.8 High
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 - Weakness
- CWE-306
- Updated
- 2026-11-02
OSVGHSA-qrx8-25qr-5r7v
n8n: MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
Impact
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). The default transport is stdio, which is not affected.
Patches
The 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.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Avoid running
@n8n/mcp-browserwith the HTTP transport; use the default stdio transport instead. - If HTTP transport is required, restrict network access to the listening port to trusted clients only using host-based firewall rules.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
- Record
GHSA-qrx8-25qr-5r7v- CVSS 4.0
- 8.8 High
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 - CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L - Weakness
- CWE-306
- Updated
- 2026-11-02
OSVROOT-APP-NPM-CVE-2026-54309 No score
CVE-2026-54309 in n8n - Patched by Root
Root has patched CVE-2026-54309 in the n8n package for Root:npm. Multiple fixed versions available.
- Record
ROOT-APP-NPM-CVE-2026-54309- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
n8nnpm |
2.26.0 up to 2.26.2 | 2.26.2 |
n8nnpm |
before 2.25.7 | 2.25.7 |
n8nRoot:npm |
before 2.19.3-aikido.7 | 2.19.3-aikido.72.19.3-aikido.22.19.3-aikido.32.19.3-aikido.42.19.3-aikido.52.19.3-aikido.62.19.3-aikido.82.19.3-aikido.92.19.3-aikido.102.19.3-aikido.112.19.3-aikido.122.19.3-aikido.132.19.3-aikido.142.19.3-aikido.15 |
@rootio/n8nRoot:npm |
before 2.19.3-root.io.7 | 2.19.3-root.io.72.19.3-root.io.22.19.3-root.io.32.19.3-root.io.42.19.3-root.io.52.19.3-root.io.62.19.3-root.io.82.19.3-root.io.92.19.3-root.io.102.19.3-root.io.112.19.3-root.io.122.19.3-root.io.132.19.3-root.io.142.19.3-root.io.15 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-54309 is a high vulnerability (CVSS 8.8) in N8n, published June 16, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.55%, the 45th percentile. Fixed in n8n 2.26.2.