Detections
Analytics

Elasticsearch 9.0.x < 9.4.9 / 9.5.x < 9.5.6 Information Disclosure (ESA-2026-210)

medium Nessus Plugin ID 375652

Synopsis

The remote host is missing a security update.

Description

The version of Elasticsearch installed on the remote host is 9.0.x prior to 9.4.9, or 9.5.x prior to 9.5.6. It is, therefore, affected by a vulnerability as referenced in the ESA-2026-210 advisory.

 - Use of Cache Containing Sensitive Information (CWE-524) in Elasticsearch can lead to information disclosure and incorrect search results via specially crafted search requests. For some query types, Elasticsearch can share cached query results between users who have field-level security restrictions and users who do not. A user restricted by field-level security can learn which documents match a value in a field that they cannot read. A restricted user can also cause users with full access to receive incomplete search results. Disclosure is only possible when a user with full access ran the same query on the same shard recently. (CVE-2026-115710)

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

Solution

Upgrade to Elasticsearch version 9.4.9, or 9.5.6 or later as appropriate for your release branch.

See Also

https://discuss.elastic.co/t/391363

Plugin Details

Severity: Medium

ID: 375652

File Name: elasticsearch_esa_2026_210.nasl

Version: 1.1

Type: Combined

Agent: unix

Family: Misc.

Published: 11/3/2026

Updated: 11/3/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.1

Percentile: 8.32

CVSS v2

Risk Factor: Low

Base Score: 3.6

Temporal Score: 2.7

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

CVSS Score Source: CVE-2026-115710

CVSS v3

Risk Factor: Medium

Base Score: 4.2

Temporal Score: 3.7

Vector: CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/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: 11/3/2026

Vulnerability Publication Date: 11/3/2026

Reference Information

CVE: CVE-2026-115710