Uncontrolled Resource Consumption in Elasticsearch Leading to Denial of Service
Uncontrolled Resource Consumption (CWE-400) in Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). A low-privileged authenticated user with permission to execute EQL sequence queries against an index they control can send a specially crafted query that triggers excessive memory consumption, causing the Elasticsearch node to crash.
Affected Versions:
- 8.x: All versions from 8.0.0 up to and including 8.19.17
- 9.x:
- All versions from 9.0.0 up to and including 9.3.6
- All versions from 9.4.0 up to and including 9.4.3
Users on the 9.5.x release line are not affected. The 9.5.0 release was the first release of that line and already includes the fix for this vulnerability.
Affected Configurations:
- All configurations where authenticated users have permission to execute EQL sequence queries are affected.
Solutions and Mitigations:
The issue is resolved in versions 8.19.18, 9.3.7, and 9.4.4.
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.
Elastic Cloud Serverless
Due to our continuous deployment and patching model, the vulnerability described in this security advisory was remediated in our Elastic Cloud Serverless offering before the public disclosure.
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-2026-56145
Problem Type: CWE-400 - Uncontrolled Resource Consumption
Impact: CAPEC-130 - Excessive Allocation