Elasticsearch ES|QL CPU Exhaustion via Exponential Data Expansion
CVE-2026-63263 Published on July 21, 2026
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.
Vulnerability Analysis
CVE-2026-63263 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Resource Exhaustion Vulnerability?
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
CVE-2026-63263 has been classified to as a Resource Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-63263
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Affected Versions
Elasticsearch:- Version 9.4.0, <= 9.4.3 is affected.
- Version 9.0.0, <= 9.3.7 is affected.
- Version 8.0.0, <= 8.19.18 is affected.