How severe is CVE-2026-72638?

CVE-2026-72638 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-72638 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-72638?

CVE-2026-72638 affects Elastic Elasticsearch. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-72638?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-72638 published?

CVE-2026-72638 was published on 2026-08-13 and last updated on 2026-09-01.

CVE-2026-72638

CVE-2026-72638 is a medium-severity vulnerability in Elastic Elasticsearch with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-674.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-674
Affected product: Elastic Elasticsearch
Published: 2026-08-13
Last modified: 2026-09-01

Description

Uncontrolled Recursion (CWE-674) in Elasticsearch can lead to denial of service via Input Data Manipulation (CAPEC-153). An authenticated user holding only low-privileged index creation permissions can submit a single request containing a specially crafted, malformed custom analysis definition that is resolved recursively without a cycle or depth check, exhausting the thread stack and terminating the affected node.

Frequently asked questions

What is CVE-2026-72638?: Uncontrolled Recursion (CWE-674) in Elasticsearch can lead to denial of service via Input Data Manipulation (CAPEC-153). An authenticated user holding only low-privileged index creation permissions can submit a single request containing a specially crafted, malformed custom analysis definition that is resolved recursively without a cycle or depth check, exhausting the thread stack and terminating the affected node.
How severe is CVE-2026-72638?: CVE-2026-72638 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-72638 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-72638?: CVE-2026-72638 affects Elastic Elasticsearch. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-72638?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-72638 published?: CVE-2026-72638 was published on 2026-08-13 and last updated on 2026-09-01.

References

https://discuss.elastic.co/t/elasticsearch-8-19-20-9-4-5-security-update-esa-2026-119/389498

Affected products (1)

cpe:2.3:a:elastic:elasticsearch:*:*:*:*:*:*:*:*

More vulnerabilities in Elastic Elasticsearch

CVE-2015-5377 — Critical (CVSS 9.8): Elasticsearch before 1.6.1 allows remote attackers to execute arbitrary code via unspecified vectors involving the…
CVE-2015-1427 — Critical (CVSS 9.8): The Groovy scripting engine in Elasticsearch before 1.3.8 and 1.4.x before 1.4.3 allows remote attackers to bypass the…
CVE-2026-72649 — High (CVSS 8.8): Deserialization of Untrusted Data (CWE-502) in the Elasticsearch machine learning component can lead to remote code…
CVE-2026-72642 — High (CVSS 8.8): The native inference process that Elasticsearch uses to evaluate uploaded machine learning models accepts a model…
CVE-2020-7014 — High (CVSS 8.8): The fix for CVE-2020-7009 was found to be incomplete. Elasticsearch versions from 6.7.0 to 6.8.7 and 7.0.0 to 7.6.1…
CVE-2020-7009 — High (CVSS 8.8): Elasticsearch versions from 6.7.0 before 6.8.8 and 7.0.0 before 7.6.2 contain a privilege escalation flaw if an…

All CVEs affecting Elastic Elasticsearch →

Other CWE-674 (Uncontrolled Recursion) vulnerabilities

CVE-2026-43185 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in…
CVE-2023-51803 — Critical (CVSS 9.8): LinuxServer.io Heimdall before 2.5.7 does not prevent use of icons that have non-image data such as the "<?php ?>"…
CVE-2021-41752 — Critical (CVSS 9.8): Stack overflow vulnerability in Jerryscript before commit e1ce7dd7271288be8c0c8136eea9107df73a8ce2 on Oct 20, 2021 due…
CVE-2018-1000618 — Critical (CVSS 9.8): EOSIO/eos eos version after commit f1545dd0ae2b77580c2236fdb70ae7138d2c7168 contains a stack overflow vulnerability in…
CVE-2025-10728 — Critical (CVSS 9.4): When the module renders a Svg file that contains a <pattern> element, it might end up rendering it recursively leading…
CVE-2026-32327 — Critical (CVSS 9.1): A bug in APR-util version 1.6.3 (and earlier) allows a stack recursion attack against any library consumer which parses…

Browse all CWE-674 (Uncontrolled Recursion) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

223.15.242.2 (ipv4-addr)