CVE & CISA-KEV Catalog

CVE-2026-72687

MEDIUM
6.5
CVSS v3
NVD

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.

How to fix

Remediation Available
ElasticsearchWindows application
Affected:9.0.0 9.4.5Fixed in:9.4.5Elastic
Affected:8.0.0 8.19.20Fixed in:8.19.20Elastic
Affected:9.5.0 9.5.1Fixed in:9.5.1Elastic

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityNone
IntegrityNone
AvailabilityHigh

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

Exploit Intelligence

0.30%probability of exploitation in 30 days
22ndpercentile

Low risk: more likely to be exploited than 22% of all known CVEs.

References

Vendor Advisory1

Related Vulnerabilities

Other CWE-789 vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2022-30522High7.590%-Fix
CVE-2026-49975High7.534%-Fix
CVE-2025-27533High7.58.7%-Fix
CVE-2017-7651High7.55.2%-Fix
CVE-2021-31811Medium5.53.4%--
CVE-2021-27906Medium5.53.3%-Fix

Common questions

How do I fix CVE-2026-72687?

Upgrade Elasticsearch to 9.4.5 or later.

Is CVE-2026-72687 being actively exploited?

Not that we know of. CVE-2026-72687 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.30% is the estimated probability that it will be exploited in the next 30 days. That is higher than 22% of all scored CVEs.

How severe is CVE-2026-72687?

CVE-2026-72687 has a CVSS v3 base score of 6.5, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-72687 affect?

Published advisories record a fix for Elasticsearch (Windows application). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-01.