How severe is CVE-2026-72656?

CVE-2026-72656 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-2026-72656 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-2026-72656?

CVE-2026-72656 affects Elastic Elasticsearch. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-72656?

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

When was CVE-2026-72656 published?

CVE-2026-72656 was published on 2026-08-13 and last updated on 2026-09-04.

CVE-2026-72656

CVE-2026-72656 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-789.

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-789
Affected product: Elastic Elasticsearch
Published: 2026-08-13
Last modified: 2026-09-04

Description

Memory Allocation with Excessive Size Value (CWE-789) in the ES|QL query processing of Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated user able to submit ES|QL queries could send a specially crafted query whose evaluation allocates an unbounded amount of heap memory, exhausting the available heap on the receiving node and causing the node to become unavailable.

Frequently asked questions

What is CVE-2026-72656?: Memory Allocation with Excessive Size Value (CWE-789) in the ES|QL query processing of Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated user able to submit ES|QL queries could send a specially crafted query whose evaluation allocates an unbounded amount of heap memory, exhausting the available heap on the receiving node and causing the node to become unavailable.
How severe is CVE-2026-72656?: CVE-2026-72656 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-2026-72656 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-2026-72656?: CVE-2026-72656 affects Elastic Elasticsearch. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-72656?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-72656 published?: CVE-2026-72656 was published on 2026-08-13 and last updated on 2026-09-04.

References

https://discuss.elastic.co/t/elasticsearch-8-18-0-9-0-0-security-update-esa-2026-111/389495

Affected products (1)

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

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Threat intelligence

Threat-intel indicators referencing this CVE:

223.15.242.2 (ipv4-addr)