Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service
Memory Allocation with Excessive Size Value (CWE-789) in the ES|QL query processing of Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated user able to submit ES|QL queries could send a specially crafted query whose evaluation allocates an unbounded amount of heap memory, exhausting the available heap on the receiving node and causing the node to become unavailable.
Affected Versions:
- 8.x: All versions from 8.11.0 up to and including 8.17.9
Versions earlier than 8.11.0 are not affected because the ES|QL query language was introduced in 8.11.0.
Affected Configurations:
- All configurations are affected. ES|QL is enabled by default.
- Exploitation requires an account that is authorized to run ES|QL queries against the cluster.
Solutions and Mitigations:
The issue is resolved in versions 8.18.0 and 9.0.0.
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.
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-2026-72656
Problem Type: CWE-789 - Memory Allocation with Excessive Size Value
Impact: CAPEC-130 - Excessive Allocation