Uncontrolled Recursion in Elasticsearch - CVE-2026-102409
Published: October 7, 2026
Vulnerability identifier: #VU153933
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-102409
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to terminate an Elasticsearch node and cause a denial of service.
The vulnerability exists due to uncontrolled recursion in the text chunking functionality when processing ES|QL queries. A remote user can submit queries that trigger excessive allocation to terminate an Elasticsearch node and cause a denial of service.
Exploitation requires ES|QL to be enabled and index read access permitting query submission. ES|QL is enabled by default.
Affected software
Elasticsearch
How to mitigate CVE-2026-102409
Install security update from vendor's website.
Elasticsearch - addressed in versions 9.4.8, 9.5.5