Detections
Analytics
Elasticsearch 8.x < 8.19.20 / 9.0.x < 9.4.5 / 9.5.x < 9.5.1 Multiple Vulnerabilities (ESA-2026-78 / ESA-2026-79 / ESA-2026-116)
medium Nessus Plugin ID 338338
Language:
Synopsis
The remote host is missing a security update.Description
The version of Elasticsearch installed on the remote host is 8.x prior to 8.19.20, or 9.0.x prior to 9.4.5, or 9.5.x prior to 9.5.1. It is, therefore, affected by multiple vulnerabilities as referenced in the ESA-2026-78, ESA-2026-79, and ESA-2026-116 advisories.- Memory Allocation with Excessive Size Value (CWE-789) in Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated user holding only read privileges on a single index can submit one small, specially crafted search request that causes an excessively large memory allocation, exhausting the JVM heap and terminating the affected node. (CVE-2026-72645)
- A flaw in Elasticsearch allows a low-privileged authenticated user to submit a single request containing a crafted user-supplied input. A specific internal component validates the input using a recursive routine and applies no bound to the length of the value being validated, so the validation causes the thread to exhaust its stack. The resulting fatal error is not handled by the surrounding execution paths and terminates the affected node process, producing a denial of service. (CVE-2026-72686)
- 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.
(CVE-2026-72687)
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 8.19.20, 9.4.5, or 9.5.1 or later as appropriate for your release branch.See Also
http://www.nessus.org/u?13e4a27e
Plugin Details
Severity: Medium
ID: 338338
File Name: elasticsearch_ESA-2026-78.nasl
Version: 1.2
Type: Combined
Agent: unix
Family: Misc.
Published: 8/20/2026
Updated: 8/21/2026
Configuration: Enable thorough checks (optional)
Supported Sensors: Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Low
Score: 3
Percentile: 23.72
CVSS v2
Risk Factor: Medium
Base Score: 6.8
Temporal Score: 5
Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C
CVSS Score Source: CVE-2026-72687
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:N/I:N/A:H
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: 8/13/2026
Vulnerability Publication Date: 8/13/2026