Uncontrolled Resource Consumption in Elasticsearch Leading to Denial of Service
Uncontrolled Resource Consumption (CWE-400) in Elasticsearch can lead to denial of service via Exponential Data Expansion (CAPEC-197). An authenticated user may submit a specially crafted query to the ES|QL engine that causes exponential CPU consumption during query evaluation. Because the resource exhaustion persists beyond query completion, repeated requests can fully exhaust the available query worker resources, rendering ES|QL queries unavailable until the node is restarted.
Affected Versions:
- 8.x: All versions from 8.0.0 up to and including 8.19.18
- 9.x:
- All versions from 9.0.0 up to and including 9.3.7
- All versions from 9.4.0 up to and including 9.4.3
Users on the 9.5.x release line are not affected by this vulnerability. The 9.5.0 release was published after the fix was applied.
Affected Configurations:
- This vulnerability affects Elasticsearch deployments where users have the ability to execute ES|QL queries.
Solutions and Mitigations:
The issue is resolved in versions 8.19.19, 9.3.8, and 9.4.4.
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-2026-63263
Problem Type: CWE-400 - Uncontrolled Resource Consumption
Impact: CAPEC-197 - Exponential Data Expansion