CVE-2026-54309 n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
Unauthenticated attackers can control the user's browser via the MCP HTTP transport, enabling JavaScript execution and data theft.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54309?
CVE-2026-54309 is a high-severity missing authorization vulnerability in N8n N8n, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-306
Which versions are affected by CVE-2026-54309?
4 open source packages ship an affected version, including n8n. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
n8n npm | All versions | 2.25.7 |
n8n npm | All versions | 2.25.7 |
n8n npm | From 2.26.0 | 2.26.2 |
n8n npm | From 2.26.0 | 2.26.2 |
Products include N8n N8n.
How do I fix CVE-2026-54309?
Upgrade n8n to a fixed version for your release line: 2.25.7 or 2.26.2.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-54309 being exploited?
There is no known exploitation of CVE-2026-54309 in the wild and no public exploit code.
Other vulnerabilities in N8n N8n
- CVE-2025-68613 n8n Improper Control of Dynamically-Managed Code Resources
- CVE-2026-21877 n8n is vulnerable to Remote Code Execution via Arbitrary File Write
- CVE-2026-21858 n8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Handling
- CVE-2026-1470 n8n Unsafe Workflow Expression Evaluation Allows Remote Code Execution
- CVE-2025-68668 n8n Vulnerable to Arbitrary Command Execution in Pyodide based Python Code Node
Sources
Also known as GHSA-qrx8-25qr-5r7v, MINI-cgqc-j2v7-46qf, ROOT-APP-NPM-CVE-2026-54309.