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

More information : https://discuss.elastic.co/t/kibana-8-19-16-9-3-5-9-4-2-security-update-esa-2026-35/386554