Auth bypass in Elastic Eck Operator

CVE-2026-78609

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.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (3.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 3.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-78609: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-78609?
CVE-2026-78609 is a medium-severity vulnerability in Elastic Eck Operator, classified under Incorrect Authorization. CVSS score: 5.4/10. Published 2026-09-02.
How severe is CVE-2026-78609?
Medium severity. CVSS v3 base score is 5.4 out of 10.