Medium severity · published Sep 2, 2026
CVE-2026-78609
Incorrect Authorization in Elastic Cloud on Kubernetes Leading to Unauthorized Modification of Data
5.4
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 4% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EO
Eck Operator · Elastic
2.6.0 through 3.4.1 · source: vendor
EC
Elastic Cloud ON Kubernetes · Elastic
2.6.0 before 3.5.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-78609
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-78609
Vendor Advisory
https://discuss.elastic.co/t/elastic-cloud-on-kubernetes-3-5-0-security-update-esa-2026-145/390105
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