CVE-2026-42400: Elastic Kibana

Medium severity, CVSS 6.5. EPSS: 0.5% chance of exploitation in the next 30 days.

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 authorization checks, causing excessive memory and CPU resource consumption that can result in a Kibana instance becoming unresponsive or crashing.

Affected products

• Elastic Kibana: from 8.0.0, before 8.19.16 (fixed in 8.19.16); from 9.0.0, before 9.3.5 (fixed in 9.3.5); from 9.4.0, before 9.4.2 (fixed in 9.4.2)

Published 2026-05-28. Last modified 2026-06-17.