What is CVE-2026-63136?

CVE-2026-63136 is a medium-severity vulnerability in Elastic Elasticsearch, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-07-21.

How severe is CVE-2026-63136?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Resource exhaustion in Elastic Elasticsearch

CVE-2026-63136

Uncontrolled Resource Consumption (CWE-400) in Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). A user with search privileges can submit a specially crafted search request that causes a data node to exhaust available heap memory, resulting in node unavailability and cluster degradation. An attacker could leverage this vulnerability to cause cluster downtime requiring manual intervention to restore service.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.002 (15.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Elastic Elasticsearch — versions 8.0.0, 9.3.0, 9.0.0

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

security@elastic.co (Vendor Advisory)

Frequently asked questions

What is CVE-2026-63136?: CVE-2026-63136 is a medium-severity vulnerability in Elastic Elasticsearch, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-07-21.
How severe is CVE-2026-63136?: Medium severity. CVSS v3 base score is 6.5 out of 10.