Elasticsearch 8.x < 8.19.18 / 9.0.x < 9.3.7 / 9.4.x < 9.4.4 Multiple Vulnerabilities (ESA-2026-56 / ESA-2026-57)

medium Nessus Plugin ID 330338

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Synopsis

The remote host is missing a security update.

Description

The version of Elasticsearch installed on the remote host is 8.x prior to 8.19.18, or 9.0.x prior to 9.3.7, 9.4.x prior to or 9.4.4. It is, therefore, affected by multiple vulnerabilities as referenced in the ESA-2026-56 and ESA-2026-57 advisories.

- Uncontrolled Resource Consumption (CWE-400) in Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). A low-privileged authenticated user with permission to execute EQL sequence queries against an index they control can send a specially crafted query that triggers excessive memory consumption, causing the Elasticsearch node to crash. (CVE-2026-56145)

- Incorrect Authorization (CWE-863) in Elasticsearch can allow an authenticated user with limited index privileges to exploit insufficient authorization controls in the ingest simulation feature. By targeting indices they are not authorized to access directly, the user can cause those indices' configured ingest pipelines to execute and return their output, potentially disclosing data processed or enriched by those pipelines. (CVE-2026-56144)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Elasticsearch version 8.19.18, 9.3.7, or 9.4.4 or later as appropriate for your release branch.

Plugin Details

Severity: Medium

ID: 330338

File Name: elasticsearch_ESA-2026-56.nasl

Version: 1.3

Type: Combined

Agent: unix

Family: Misc.

Published: 7/28/2026

Updated: 8/12/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.75

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:N/A:N

CVSS Score Source: CVE-2026-56144

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:elastic:elasticsearch, cpe:/a:elasticsearch:elasticsearch

Required KB Items: installed_sw/Elasticsearch

Exploit Ease: No known exploits are available

Patch Publication Date: 7/21/2026

Vulnerability Publication Date: 7/21/2026

Reference Information

CVE: CVE-2026-56144, CVE-2026-56145

IAVA: 2026-A-0760

Detections

Analytics