What is CVE-2026-56143?

CVE-2026-56143 is a medium-severity vulnerability in Elastic Elasticsearch, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.9/10. Published 2026-09-01.

How severe is CVE-2026-56143?

Medium severity. CVSS v3 base score is 4.9 out of 10.

Resource exhaustion in Elastic Elasticsearch

CVE-2026-56143

Allocation of Resources Without Limits or Throttling (CWE-770) in Elasticsearch can lead to a denial of service via Excessive Allocation (CAPEC-130). A user with elevated privileges can submit a specially crafted request that causes excessive memory consumption, which may render the affected node unavailable.

Published 2026-09-01 · last modified 2026-09-04.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.8th percentile), scored 2026-10-17.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Elastic Elasticsearch

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

discuss.elastic.co/t/elasticsearch-8-19-20-9-3-0-security-update-esa-2026-47/39… (Vendor Advisory)

Frequently asked questions

What is CVE-2026-56143?: CVE-2026-56143 is a medium-severity vulnerability in Elastic Elasticsearch, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.9/10. Published 2026-09-01.
How severe is CVE-2026-56143?: Medium severity. CVSS v3 base score is 4.9 out of 10.