What is CVE-2026-42400?

CVE-2026-42400 is a medium-severity vulnerability in Elastic Kibana, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-05-28.

How severe is CVE-2026-42400?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Resource exhaustion in Elastic Kibana

CVE-2026-42400

Uncontrolled Resource Consumption (CWE-400) in Kibana can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated user can send a specially crafted compressed request payload that is processed prior to authorizatio…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.000 (14.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Elastic Kibana — versions 9.4.0, 9.0.0, 8.0.0

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

security@elastic.co (Vendor Advisory)

Frequently asked questions

What is CVE-2026-42400?: CVE-2026-42400 is a medium-severity vulnerability in Elastic Kibana, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-05-28.
How severe is CVE-2026-42400?: Medium severity. CVSS v3 base score is 6.5 out of 10.