CVE-2026-72638: 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 Input Data Manipulation (CAPEC-153). An authenticated user holding only low-privileged index creation permissions can submit a single request containing a specially crafted, malformed custom analysis definition that is resolved recursively without a cycle or depth check, exhausting the thread stack and terminating the affected node.

Affected products

• Elastic Elasticsearch: from 8.0.0, before 8.19.20 (fixed in 8.19.20); from 9.0.0, before 9.4.5 (fixed in 9.4.5)

Published 2026-08-13. Last modified 2026-09-01.