Uncontrolled Recursion in Elasticsearch Leading to Denial of Service

Summary

Uncontrolled Recursion (CWE-674) in Elasticsearch can lead to denial of service via Serialized Data with Nested Payloads (CAPEC-230). An unauthenticated attacker with network access to the remote cluster server interface of a node can send a specially crafted request that causes the node to terminate. No credentials are required. The attacker can repeat the request against each reachable node.

Remediation

1. Inventory every Elastic Elasticsearch deployment, including staging.
2. No fixed version appears in the public sources yet. Check the references below and the vendor directly.

References

• Referencehttps://discuss.elastic.co/t/elasticsearch-8-19-24-9-4-9-9-5-6-security-update-esa-2026-201/391356