CVE-2026-72678
Elasticsearch does not validate a size value taken from a user-supplied input before that value is used to reserve memory for an internal data structure.
Impact
Elasticsearch does not validate a size value taken from a user-supplied input before that value is used to reserve memory for an internal data structure. An authenticated user holding only read privileges can submit a single small crafted request to a product API endpoint that causes the node to attempt an excessively large allocation. The resulting memory exhaustion raises a fatal error that terminates the Elasticsearch node process, causing a denial of service for the affected node and degrading cluster health. The defect is not volumetric, so a single request is sufficient regardless of the heap size configured on the target node.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Elastic | Elasticsearch | from 8.19.0 before 8.19.20 from 9.4.0 before 9.4.5 from 9.5.0 before 9.5.1 |