Junglewise Threat Intelligence

CVE-2026-42400: Elastic Kibana denial of service via uncontrolled resource consumption

CVE-2026-42400 · Severity: medium · CVSS 6.5 · Published 2026-05-28

Technologies: Elastic Kibana. Vendors: Elastic.

Executive brief

Kibana, a popular data visualization and management platform for the Elastic Stack, is vulnerable to a denial-of-service attack. An authenticated user can send a specially crafted compressed request that consumes excessive system memory and CPU. This can cause the Kibana service to become unresponsive or crash, disrupting data analysis and monitoring operations.

Technical details

A vulnerability in Kibana (CWE-400) allows for uncontrolled resource consumption via excessive allocation (CAPEC-130). The flaw exists because Kibana processes compressed request payloads before performing authorization checks. An authenticated attacker can exploit this by sending a malicious payload that triggers high CPU and memory usage during decompression or processing. This results in a denial of service (DoS) where the Kibana instance crashes or stops responding to legitimate traffic. The issue is resolved in versions 8.19.16, 9.3.5, and 9.4.2.

Affected products

  • Elastic Kibana 8.0.0 to 8.19.15, 9.0.0 to 9.3.4, 9.4.0 to 9.4.1

Timeline

  • 2026-05-28: disclosed
  • 2026-05-28: advisory
  • 2026-05-28: patched: Remediated in Elastic Cloud Serverless prior to public disclosure.

References

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