Description

Improper Handling of Highly Compressed Data (CWE-409) in Kibana can lead to a denial of service via Excessive Allocation (CAPEC-130). An authenticated user holding Streams management privileges could supply specially crafted content that expands to a far larger volume of data during processing, exhausting the memory available to Kibana. The Kibana process is terminated by the host and remains unavailable to all users until the service is restarted.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-09-01T20:17:16.373Z",
  "pubdate": "2026-09-01T20:17:16.373Z",
  "executiveSummary": "This vulnerability involves the improper handling of highly compressed data within Kibana, classified under CWE-409 (Improper Handling of Highly Compressed Data).\nThe flaw allows an authenticated user with Streams management privileges to trigger a Denial of Service (DoS) condition via Excessive Allocation (CAPEC-130).\nBy submitting a specially crafted payload designed to achieve an extreme compression ratio, an attacker can force the Kibana service to perform massive memory allocation during the decompression process.\nThis excessive resource consumption leads to memory exhaustion, causing the host operating system to terminate the Kibana process.\nThe impact is a total loss of availability for the Kibana service, requiring manual intervention in the form of a service restart to restore operations.\nExploitation requires the attacker to possess authenticated access to the Streams management functionality, limiting the threat surface to authorized users or compromised accounts with sufficient privilege levels.",
  "technicalDetails": "The root cause of this vulnerability lies in the insufficient validation or resource management when processing highly compressed data streams within the Kibana application component responsible for managing Streams.\nThe application fails to impose adequate limits on the memory allocation required during the decompression phase, making it susceptible to decompression bombs.\nThe attack flow initiates when an authenticated user, leveraging existing Streams management privileges, crafts an input payload that exhibits a high ratio of decompressed data to compressed data.\nUpon submission of this payload to the vulnerable endpoint, the Kibana server initiates a decompression operation to process the content.\nAs the algorithm expands the compressed data, the memory footprint of the process grows exponentially, far exceeding the intended or available buffer sizes.\nBecause the system lacks a circuit-breaker or hard memory limit on the expansion process, the memory request triggers an Out-Of-Memory (OOM) state at the application or host level.\nThis forces the operating system kernel or the container runtime to kill the Kibana process to prevent system-wide instability, resulting in immediate service disruption.\nThe vulnerability is specifically tied to the processing logic within the Streams management infrastructure. The necessity of administrative-level 'Streams management' privileges acts as a critical prerequisite, preventing unauthenticated external actors from triggering the condition remotely without first gaining a foothold in the application.\nPost-exploitation impact is limited to the unavailability of the Kibana instance. While the service is terminated, it does not inherently lead to remote code execution or unauthorized data exfiltration; however, the resulting downtime can significantly impact observability, logging, and security monitoring pipelines that rely on the affected Kibana instance for data visualization and management."
}