CVE-2026-78609: Elastic Cloud On Kubernetes

Medium severity, CVSS 5.4. EPSS: 0.2% chance of exploitation in the next 30 days.

Incorrect Authorization (CWE-863) in Elastic Cloud on Kubernetes (ECK) can lead to unauthorized modification of data via Metadata Spoofing (CAPEC-690). An actor holding limited Kubernetes permissions confined to a single namespace could cause attacker-controlled certificate material to be included in the Elasticsearch client trust bundle managed by ECK in a separate namespace.

Affected products

• Elastic Elastic Cloud On Kubernetes: from 2.6.0, before 3.5.0 (fixed in 3.5.0)

Published 2026-09-02. Last modified 2026-09-04.