Uncontrolled Resource Consumption in Elasticsearch Leading to Denial of Service
Uncontrolled Resource Consumption (CWE-400) in Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). A user with search privileges can submit a specially crafted search request that causes a data node to exhaust available heap memory, resulting in node unavailability and cluster degradation. An attacker could leverage this vulnerability to cause cluster downtime requiring manual intervention to restore service.
Affected Versions:
- 8.x: All versions from 8.0.0 up to and including 8.19.14
- 9.x:
- All versions from 9.0.0 up to and including 9.2.8
- All versions from 9.3.0 up to and including 9.3.3
The 9.4.x release line is not affected. The fix was incorporated prior to the initial 9.4.0 release and that line was never vulnerable.
Affected Configurations:
- All configurations are affected, including deployments with security enabled that permit authenticated users to execute search requests.
Solutions and Mitigations:
The issue is resolved in versions 8.19.15, 9.2.9, and 9.3.4.
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.
Elastic Cloud Serverless
Due to our continuous deployment and patching model, the vulnerability described in this security advisory was remediated in our Elastic Cloud Serverless offering before the public disclosure.
Severity: CVSSv3.1: Medium ( 6.5 ) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVE ID: CVE-2026-63136
Problem Type: CWE-400 - Uncontrolled Resource Consumption
Impact: CAPEC-130 - Excessive Allocation