# Elastic Cloud on Kubernetes 3.5.0 Security Update (ESA-2026-146)

**URL:** <https://discuss.elastic.co/t/elastic-cloud-on-kubernetes-3-5-0-security-update-esa-2026-146/390106>\
**Category:** Security Announcements\
**Created:** [September 1, 2026, 10:32pm UTC](https://discuss.elastic.co/t/elastic-cloud-on-kubernetes-3-5-0-security-update-esa-2026-146/390106 "2026-09-01T22:32:05Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Bryan\_Garcia](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/bryan_garcia/32/148179_2.png) [@Bryan\_Garcia](https://discuss.elastic.co/u/Bryan_Garcia)\
**Post date:** [September 1, 2026, 10:32pm UTC](https://discuss.elastic.co/t/elastic-cloud-on-kubernetes-3-5-0-security-update-esa-2026-146/390106/1 "2026-09-01T22:32:05Z")

</div>

**Incomplete Cleanup in Elastic Cloud on Kubernetes Leading to Unauthorized Cross-Namespace Credential Retention**

Incomplete Cleanup (CWE-459) in Elastic Cloud on Kubernetes (ECK) can lead to unauthorized access via Privilege Abuse (CAPEC-122). Authentication credentials persist after a cross-namespace association has been denied by RBAC enforcement, allowing a low-privileged tenant to retain unauthorized read access to the associated Elasticsearch cluster.

**Affected Versions:**

- All versions from 2.6.0 up to and including 3.4.1

**Affected Configurations:**  
Deployments where cross-namespace resource associations have been established and are subsequently subject to RBAC enforcement -- either through enabling RBAC controls on the operator or through revocation of previously granted cross-namespace permissions. Deployments that have never used cross-namespace associations, or deployments in which RBAC enforcement has never been applied, are not affected.

**Solutions and Mitigations:**  
The issue is resolved in Elastic Cloud on Kubernetes version 3.5.0.

**For Users that Cannot Upgrade:**  
There are no workarounds for this vulnerability.

**Indicators of Compromise (IOC)**  
No specific indicators of compromise have been identified for this vulnerability.

**Severity:** CVSSv3.1: Low ( 3.5 ) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N  
**CVE ID:** CVE-2026-78600  
**Problem Type:** CWE-459 - Incomplete Cleanup  
**Impact:** Impact: CAPEC-122 - Privilege Abuse