Vulnerability · Published Aug 13, 2026 · Assigned by elastic
CVE-2026-72687Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service
Medium 6.5
In plain English
A medium-severity security flaw in Elasticsearch from Elastic. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Elastic | Elasticsearch | 8.0.0 – through 8.19.199.0.0 – through 9.4.49.5.0 |
Weakness: CWE-789 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H