# Elasticsearch 8.19.17, 9.3.6, 9.4.3 Security Update (ESA-2026-42)

**URL:** <https://discuss.elastic.co/t/elasticsearch-8-19-17-9-3-6-9-4-3-security-update-esa-2026-42/387439>\
**Category:** Security Announcements\
**Created:** [July 1, 2026, 1:50pm UTC](https://discuss.elastic.co/t/elasticsearch-8-19-17-9-3-6-9-4-3-security-update-esa-2026-42/387439 "2026-07-01T13:50:06Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![kruskall](https://avatars.discourse-cdn.com/v4/letter/k/ac91a4/32.png) [@kruskall](https://discuss.elastic.co/u/kruskall)\
**Post date:** [July 1, 2026, 1:50pm UTC](https://discuss.elastic.co/t/elasticsearch-8-19-17-9-3-6-9-4-3-security-update-esa-2026-42/387439/1 "2026-07-01T13:50:07Z")

</div>

**Uncontrolled Recursion in Elasticsearch Leading to Denial of Service**

Uncontrolled Recursion (CWE-674) in Elasticsearch can lead to a denial of service via Excessive Allocation (CAPEC-130). An authenticated user can submit a specially crafted query that causes excessive resource consumption while the request is processed, which may render the affected node unavailable.

**Affected Versions:**

- 8.x: All versions from 8.0.0 up to and including 8.19.16
- 9.x:
  - All versions from 9.0.0 up to and including 9.4.2
  - The 9.3 release line is affected up to and including 9.3.5

**Affected Configurations:**

- All configurations are affected. Exploitation requires an authenticated account with privileges to submit queries; no administrative privileges are required.

**Solutions and Mitigations:**

The issue is resolved in versions 8.19.17, 9.3.6, and 9.4.3.

**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-2026-56148  
**Problem Type:** CWE-674 - Uncontrolled Recursion  
**Impact:** CAPEC-130 - Excessive Allocation