Description

Allocation of Resources Without Limits or Throttling (CWE-770) in Elasticsearch can lead to a denial of service via Excessive Allocation (CAPEC-130). A user with elevated privileges can submit a specially crafted request that causes excessive memory consumption, which may render the affected node unavailable.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.9",
  "pubDate": "2026-09-01T20:17:14.990Z",
  "pubdate": "2026-09-01T20:17:14.990Z",
  "executiveSummary": "This vulnerability is classified as an Allocation of Resources Without Limits or Throttling (CWE-770), specifically manifesting as an Excessive Allocation (CAPEC-130) issue within Elasticsearch.\nThe flaw resides in the handling of incoming requests, where a lack of restrictive resource boundaries allows for uncontrolled memory consumption.\nSuccessful exploitation results in a Denial of Service (DoS) condition, rendering the affected Elasticsearch node unresponsive or causing it to crash due to Out-Of-Memory (OOM) errors.\nThe vulnerability is contingent upon the attacker possessing elevated privileges within the Elasticsearch environment.\nRisk implications include significant service disruption and potential operational downtime, as an authenticated actor can intentionally induce node instability.\nThe primary requirement for exploitation is the ability to submit crafted requests that bypass standard resource usage expectations, necessitating rigorous access control and monitoring.",
  "technicalDetails": "The core vulnerability stems from the absence of sufficient resource constraints during the processing of specific, specially crafted requests submitted to the Elasticsearch API.\nWhen a user with elevated privileges submits such a request, the Elasticsearch engine fails to throttle or limit the memory allocation associated with the execution of that specific operation.\nThis behavior aligns with the definition of CWE-770, where the system fails to verify if the requested resource allocation is within reasonable limits, thereby allowing a single request to consume a disproportionate amount of the node's available memory heap.\nThe attack flow begins with the authenticated user interacting with the Elasticsearch REST API. The attacker crafts a request designed to trigger an intensive resource-heavy query or aggregation that lacks inherent pagination or memory-capping mechanisms.\nUpon receipt, the Elasticsearch node attempts to fulfill the request by allocating memory to hold the intermediate results or the data structure required for processing.\nBecause the system lacks effective limits on these allocations, the request forces the Java Virtual Machine (JVM) to perform excessive memory reservation. This triggers high garbage collection pressure or rapid heap growth, eventually leading to an Out-Of-Memory exception.\nThe impact is a node-level Denial of Service; the node may either enter a hang state, become unable to process further queries, or terminate abruptly due to OOM killer intervention at the OS level.\nSince this requires elevated privileges, the attack vector is restricted to malicious or compromised internal actors. The vulnerability highlights a lack of 'circuit breakers' or resource quotas that should be applied to high-privilege operations to ensure system stability regardless of the input provided.\nThis vulnerability is not limited to a specific interface but is inherent to the way Elasticsearch handles resource-intensive requests originating from users with sufficient permissions to execute complex queries or management actions."
}