How severe is CVE-2026-54309?

CVE-2026-54309 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2026-54309 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-54309?

CVE-2026-54309 affects N8n. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-54309?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-54309 have an EU (EUVD) identifier?

Yes. CVE-2026-54309 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38468.

When was CVE-2026-54309 published?

CVE-2026-54309 was published on 2026-06-23 and last updated on 2026-06-25.

CVE-2026-54309

CVE-2026-54309 is a critical-severity vulnerability in N8n with a CVSS 3.x base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
CVSS v4: 8.8
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-38468
Weakness: CWE-306
Affected product: N8n
Published: 2026-06-23
Last modified: 2026-06-25

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.

Frequently asked questions

What is CVE-2026-54309?: 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.
How severe is CVE-2026-54309?: CVE-2026-54309 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2026-54309 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-54309?: CVE-2026-54309 affects N8n. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-54309?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-54309 have an EU (EUVD) identifier?: Yes. CVE-2026-54309 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38468.
When was CVE-2026-54309 published?: CVE-2026-54309 was published on 2026-06-23 and last updated on 2026-06-25.

References

https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v

Affected products (1)

cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*

More vulnerabilities in N8n

CVE-2026-21858 — Critical (CVSS 10.0): n8n is an open source workflow automation platform. Versions starting with 1.65.0 and below 1.121.0 enable an attacker…
CVE-2026-54305 — Critical (CVSS 9.9): n8n is an open source workflow automation platform. Prior to 1.123.55, 2.25.7, and 2.26.2, three EE endpoints used by…
CVE-2026-44791 — Critical (CVSS 9.9): n8n is an open source workflow automation platform. Prior to 1.123.43, 2.22.1, and 2.20.7, an authenticated user with…
CVE-2026-44789 — Critical (CVSS 9.9): n8n is an open source workflow automation platform. Prior to 1.123.43, 2.22.1, and 2.20.7, an authenticated user with…
CVE-2026-54310 — Critical (CVSS 9.9): n8n is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, an authenticated user with permission…
CVE-2026-27577 — Critical (CVSS 9.9): n8n is an open source workflow automation platform. Prior to versions 2.10.1, 2.9.3, and 1.123.22, additional exploits…

All CVEs affecting N8n →

Other CWE-306 (Missing Authentication for Critical Function) vulnerabilities

CVE-2026-50242 — Critical (CVSS 10.0): In JetBrains Hub before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429…
CVE-2026-49257 — Critical (CVSS 10.0): mcp-pinot is a Python-based Model Context Protocol (MCP) server for interacting with Apache Pinot. In versions 3.0.1…
CVE-2026-46846 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46803 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46800 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites).…
CVE-2026-46798 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites).…

Browse all CWE-306 (Missing Authentication for Critical Function) vulnerabilities →