CVE-2026-0531 is a resource exhaustion vulnerability classified under CWE-770 (Allocation of Resources Without Limits or Throttling) found in Elastic Kibana Fleet. The flaw arises when the application processes a specially crafted bulk retrieval request that triggers redundant database retrieval operations. These operations cause excessive memory allocation without any throttling or limits, leading to rapid consumption of server memory resources. The attacker must have at least viewer-level privileges, which provide read access to agent policies, enabling them to craft such requests. Because the vulnerability exploits resource management flaws, it results in a denial-of-service condition by crashing the Kibana server, rendering it unavailable to legitimate users. The vulnerability affects multiple Kibana versions, including 7.10.0, 8.0.0, 9.0.0, and 9.2.0. The CVSS v3.1 base score is 6.5 (medium severity), reflecting network attack vector, low attack complexity, required privileges, no user interaction, and impact limited to availability. No known public exploits exist yet, but the vulnerability poses a risk to environments relying on Kibana for monitoring and management. The lack of throttling or resource limits in handling bulk requests is the root cause, highlighting a need for improved input validation and resource management controls in Kibana Fleet components.

For European organizations, this vulnerability can cause significant operational disruptions by crashing Kibana servers used for log analysis, security monitoring, and infrastructure observability. The denial-of-service impact affects availability, potentially delaying incident response and operational decision-making. Organizations in sectors such as finance, telecommunications, energy, and government that rely heavily on Elastic Stack for real-time monitoring are particularly vulnerable. The attack requires only viewer-level privileges, which may be more widely distributed internally, increasing the attack surface. Disruptions could lead to compliance issues under regulations like GDPR if monitoring and logging capabilities are impaired. Additionally, prolonged downtime could affect service level agreements and damage organizational reputation. While no data confidentiality or integrity loss is indicated, the loss of availability in critical monitoring tools can indirectly increase risk exposure to other threats.

To mitigate CVE-2026-0531, organizations should first audit and restrict the assignment of viewer roles to trusted personnel only, minimizing the number of users with read access to agent policies. Implement strict access controls and monitor for unusual bulk retrieval requests that could indicate exploitation attempts. Employ resource monitoring and alerting on Kibana servers to detect abnormal memory consumption early. Where possible, isolate Kibana Fleet components in segmented network zones to limit potential attack impact. Apply vendor patches promptly once released, as Elastic is expected to address the lack of throttling and resource limits in future updates. Until patches are available, consider implementing rate limiting or request filtering at the network or proxy level to block suspicious bulk retrieval requests. Regularly review Kibana logs for signs of repeated or malformed requests targeting agent policies. Finally, maintain up-to-date backups and incident response plans to recover quickly from potential service outages.