Executive brief
Elastic Cloud on Kubernetes (ECK) is a Kubernetes operator that manages Elasticsearch deployments. In multi-tenant environments, an attacker with limited permissions in one Kubernetes namespace could inject malicious certificates into Elasticsearch's trust bundle used in a separate namespace, potentially allowing them to intercept or modify Elasticsearch client communications. This vulnerability only affects deployments where Elasticsearch client certificate authentication is in use.
Technical details
This vulnerability is an incorrect authorization flaw (CWE-863) allowing metadata spoofing (CAPEC-690). An attacker with limited Kubernetes permissions confined to a single namespace can cause attacker-controlled certificate material to be included in the Elasticsearch client trust bundle managed by ECK in a separate namespace. The vulnerability requires network access and the attacker to already hold some Kubernetes permissions within their own namespace. By injecting rogue certificates, an attacker can potentially decrypt or forge Elasticsearch client communications. The issue is resolved in ECK version 3.5.0; all versions from 2.6.0 through 3.4.1 are affected. No workarounds are available.
Affected products
- Elastic Cloud on Kubernetes 2.6.0 through 3.4.1
Timeline
- 2026-09-01: disclosed
- 2026-09-01: patched: Fixed in version 3.5.0