Medium · published August 14, 2026
A flaw in Elasticsearch allows an authenticated user with the privileges required to invoke the simulate pipeline API endpoint (https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-ingest-simulate) to submit a request that causes a self-referential data structure to be created. When a specific internal component later processes that structure, the operation recurses without bound and raises a fatal error that is not handled by the surrounding execution path, terminating the affected node process and resulting in a denial of service.
| Product | Versions | Fixed in |
|---|---|---|
| elastic/elasticsearch | ≥ 5.0.0, < 8.19.19 | 8.19.19 |
| elastic/elasticsearch | ≥ 9.3.0, < 9.3.8 | 9.3.8 |
| elastic/elasticsearch | ≥ 9.4.0, < 9.4.4 | 9.4.4 |