# CVE-2026-56143: Elastic Elasticsearch resource exhaustion denial of service

Source: https://junglewise.ai/threats/cve-2026-56143-elastic-elasticsearch-resource-exhaustion-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-01. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-56143 · Severity: medium · CVSS 4.9 · Published 2026-09-01

Elasticsearch, a widely-used search and analytics engine, contains a vulnerability that allows privileged users to submit specially crafted requests causing excessive memory consumption. An attacker exploiting this flaw can render individual Elasticsearch nodes unavailable, disrupting search, logging, and analytics operations that depend on the service.

Technologies: [Elasticsearch](https://junglewise.ai/threats/technologies/elasticsearch). Vendors: [Elastic](https://junglewise.ai/threats/vendors/elastic).

## Quick answers

**Is CVE-2026-56143 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-56143 being exploited in the wild.

**How severe is CVE-2026-56143?** Medium severity, with a CVSS score of 4.9, published 1 September 2026.

**Which products and versions are affected?** Elasticsearch 8.0.0 to 8.19.19, 9.0.0 to 9.2.8.

**Is there a fix for CVE-2026-56143?** A patch was published on 2026-09-01: Fixed in versions 8.19.20 and 9.3.0 and later Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-56143 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-56143?** Check whether you run Elasticsearch at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This is a resource exhaustion vulnerability (CWE-770) in Elasticsearch where the system fails to properly throttle or limit memory allocation in response to certain requests. The vulnerability requires elevated privileges to exploit and network access to the Elasticsearch instance. An attacker can craft a malicious request that triggers excessive memory allocation, causing the affected node to become unavailable due to out-of-memory conditions. The issue is resolved in Elasticsearch versions 8.19.20 and 9.3.0 or later; no workarounds are available for unpatched systems.

## Affected products

- Elastic Elasticsearch 8.0.0 to 8.19.19, 9.0.0 to 9.2.8

## Timeline

- 2026-09-01: disclosed
- 2026-09-01: patched: Fixed in versions 8.19.20 and 9.3.0 and later

## References

- [https://discuss.elastic.co/t/elasticsearch-8-19-20-9-3-0-security-update-esa-2026-47/390084](https://discuss.elastic.co/t/elasticsearch-8-19-20-9-3-0-security-update-esa-2026-47/390084)

## Related threats

- [Elasticsearch denial of service in phonetic analysis encoders](https://junglewise.ai/threats/cve-2026-115715-allocation-of-resources-without-limits-or-throttling-cwe-770-in)
- [Elasticsearch cache information disclosure via field-level security bypass](https://junglewise.ai/threats/cve-2026-115710-use-of-cache-containing-sensitive-information-cwe-524-in)
- [Elasticsearch incorrect authorization in field-level security](https://junglewise.ai/threats/cve-2026-115298-incorrect-authorization-cwe-863-in-elasticsearch-can-lead-to)
- [Elasticsearch uncontrolled recursion denial of service](https://junglewise.ai/threats/cve-2026-115290-uncontrolled-recursion-cwe-674-in-elasticsearch-can-lead-to)
- [Elasticsearch authorization bypass in cross-cluster search](https://junglewise.ai/threats/cve-2026-103009-authorization-bypass-through-user-controlled-key-cwe-639-in)