# CVE-2026-72687: Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service

> CVE-2026-72687: Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service. CVSS 6.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-72687
Last updated: 2026-09-01T14:58:27Z

- Published: 2026-08-13 19:11 UTC · Updated: 2026-09-01 14:58 UTC · Assigner: elastic
- CVSS: 6.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.42%, 36th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-789

## Description

A flaw in Elasticsearch allows a low-privileged authenticated user to submit a single small request containing a forged opaque identifier. Elasticsearch decodes and deserializes the identifier before confirming that it was legitimately issued by the cluster, and a size value carried inside the identifier drives an allocation that is neither capped nor accounted for by the available memory-usage controls. The resulting out-of-memory condition is fatal and terminates the affected node process, resulting in a denial of service.

## Affected vendors and products

- Elastic: Elasticsearch

## Tracked companies

- [Elastic Cloud](https://rewindex.com/company/elastic-cloud.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-72687)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-72687)
- [https://discuss.elastic.co/t/elasticsearch-8-19-20-9-4-5-9-5-1-security-update-esa-2026-79/389506](https://discuss.elastic.co/t/elasticsearch-8-19-20-9-4-5-9-5-1-security-update-esa-2026-79/389506)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-72687 · Markdown: https://rewindex.com/cve/CVE-2026-72687.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-72687 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:18.402Z