Is CVE-2026-54309 in the CISA KEV catalog?

No. CVE-2026-54309 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-54309?

CVE-2026-54309 has a CVSS v4 base score of 8.8 (HIGH).

What is the EPSS score for CVE-2026-54309?

CVE-2026-54309 has an EPSS score of 0.41% (33th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-54309

HIGH

8.8

CVSS v4

NVD

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.

CWE-306

CVSS v4 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Impact

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

Exploit Intelligence

0.41%probability of exploitation in 30 days

33rdpercentile

Low risk: more likely to be exploited than 33% of all known CVEs.

References

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

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-23.