CVE-2026-78609 Incorrect Authorization in Elastic Cloud on Kubernetes Leading to Unauthorized Modification of Data

Medium 5.4 Published 2 Sep 2026 Updated 2 Sep 2026

Attackers with limited Kubernetes permissions can spoof metadata to inject malicious certificates into Elasticsearch trust bundles, enabling unauthorized data modification.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-78609?

CVE-2026-78609 is a medium-severity missing authorization vulnerability in Elastic Eck Operator, published on 2 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Weakness: CWE-863

Which versions are affected by CVE-2026-78609?

It affects 1 product.

Products include Elastic Elastic Cloud on Kubernetes.

How do I fix CVE-2026-78609?

No fix has been published for CVE-2026-78609 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-78609 being exploited?

There is no known exploitation of CVE-2026-78609 in the wild and no public exploit code.

Sources

Also known as GHSA-h699-694r-9xxf.