Vulnerability in Elastic Elasticsearch
CVE-2026-72687
A flaw in Elasticsearch allows a low-privileged authenticated user to submit a single small request containing a forged opaque identifier. Elasticsearch decodes and deserializes the identifier before confirming that it was legitimately issued by the cluster, and a size value carried inside the identifier drives an allocation that is neither capped nor accounted for by the available memory-usage controls. The resulting out-of-memory condition is fatal and terminates the affected node process, resulting in a denial of service.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (33.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.8% 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 — versions 8.0.0, 9.0.0, 9.5.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-72687?
- CVE-2026-72687 is a medium-severity vulnerability in Elastic Elasticsearch, classified under CWE-789. CVSS score: 6.5/10. Published 2026-08-13.
- How severe is CVE-2026-72687?
- Medium severity. CVSS v3 base score is 6.5 out of 10.