What is CVE-2026-63140?

CVE-2026-63140 is a medium-severity vulnerability in Elastic Elasticsearch, classified under Reachable Assertion. CVSS score: 6.5/10. Published 2026-07-21.

How severe is CVE-2026-63140?

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

Vulnerability in Elastic Elasticsearch

CVE-2026-63140

Reachable Assertion (CWE-617) in Elasticsearch can lead to denial of service via Input Data Manipulation (CAPEC-153). A specially crafted search request containing a null value in a specific query clause causes an internal assertion to be…

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 9.0.0, 9.4.0, 8.0.0

Weakness classification (CWE)

CWE-617 — Reachable Assertion

References

security@elastic.co

Frequently asked questions

What is CVE-2026-63140?: CVE-2026-63140 is a medium-severity vulnerability in Elastic Elasticsearch, classified under Reachable Assertion. CVSS score: 6.5/10. Published 2026-07-21.
How severe is CVE-2026-63140?: Medium severity. CVSS v3 base score is 6.5 out of 10.