Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2026-08-19 08:39

Modified

2026-09-08 08:34

Summary

Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service

Details

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.

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "elasticsearch",
        "purl": "pkg:bitnami/elasticsearch"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.19.20"
            },
            {
              "introduced": "9.0.0"
            },
            {
              "fixed": "9.4.5"
            },
            {
              "introduced": "9.5.0"
            },
            {
              "fixed": "9.5.1"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-72687"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:elastic:elasticsearch:*:*:*:*:*:*:*:*",
      "cpe:2.3:a:elastic:elasticsearch:*:*:*:*:*:maven:*:*"
    ],
    "severity": "Medium"
  },
  "details": "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.",
  "id": "BIT-elasticsearch-2026-72687",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2026-08-19T08:39:51.712Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://discuss.elastic.co/t/elasticsearch-8-19-20-9-4-5-9-5-1-security-update-esa-2026-79/389506"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72687"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service"
}

CVE-2026-72687 (GCVE-0-2026-72687)

Vulnerability from cvelistv5 – Published: 2026-08-13 19:11 – Updated: 2026-08-13 20:34

Title

Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service

Summary

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-13 20:23 UTC

CWE

CWE-789 - Memory Allocation with Excessive Size Value

Assigner

elastic mitre root

References

1 reference

URL	Tags
https://discuss.elastic.co/t/elasticsearch-8-19-2…

Impacted products

1 product

Vendor	Product	Version
Elastic	Elasticsearch	Affected: 8.0.0 , ≤ 8.19.19 (semver) Affected: 9.0.0 , ≤ 9.4.4 (semver) Affected: 9.5.0 (semver)

Show details on NVD website

JSON

To clipboard

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        "metrics": [
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            "other": {
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                "id": "CVE-2026-72687",
                "options": [
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                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-13T20:23:14.534132Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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        "providerMetadata": {
          "dateUpdated": "2026-08-13T20:34:33.600Z",
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      "metrics": [
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            "availabilityImpact": "HIGH",
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            "confidentialityImpact": "NONE",
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    "dateReserved": "2026-08-10T11:17:58.731Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.