CVE-2026-63144: Elastic Elasticsearch

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Uncontrolled Recursion (CWE-674) in Elasticsearch can lead to denial of service via a specially crafted search request submitted by a low-privileged authenticated user. A user with read-level index access can submit a request that triggers unbounded recursive processing within the Elasticsearch query evaluation component, causing a fatal error that terminates the affected node. In single-node deployments, this results in complete service outage; in multi-node clusters, it causes repeated node restarts and sustained availability degradation.

Affected products

• Elastic Elasticsearch: from 8.19.0, before 8.19.19 (fixed in 8.19.19); from 9.3.0, before 9.3.8 (fixed in 9.3.8); from 9.4.0, before 9.4.4 (fixed in 9.4.4)

Published 2026-07-21. Last modified 2026-08-03.