# CVE-2026-72678

## Summary

- **CVE ID:** CVE-2026-72678
- **Severity:** MEDIUM
- **CVSS Score:** 6.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-789
- **Published:** Aug 13, 2026
- **Last Modified:** Aug 13, 2026

## Description

Elasticsearch does not validate a size value taken from a user-supplied input before that value is used to reserve memory for an internal data structure. An authenticated user holding only read privileges can submit a single small crafted request to a product API endpoint that causes the node to attempt an excessively large allocation. The resulting memory exhaustion raises a fatal error that terminates the Elasticsearch node process, causing a denial of service for the affected node and degrading cluster health. The defect is not volumetric, so a single request is sufficient regardless of the heap size configured on the target node.

## Affected Products

- Elastic — Elasticsearch (8.19.0)
- Elastic — Elasticsearch (9.4.0)
- Elastic — Elasticsearch (9.5.0)

## References

- [CNA](https://discuss.elastic.co/t/elasticsearch-8-19-20-9-4-5-9-5-1-security-update-esa-2026-80/389507)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.33%
- **EPSS Percentile:** 26.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._