CVE-2026-26937: 
Kibana vulnerability analysis and mitigation

CVE-2026-26937 is an Uncontrolled Resource Consumption (CWE-400) vulnerability in the Timelion component of Elastic Kibana that can lead to Denial of Service via Input Data Manipulation (CAPEC-153). It affects Kibana versions 8.0.0 through 8.19.10 and 9.0.0 through 9.2.4. The vulnerability was published on February 26, 2026, with patches released shortly after. It carries a CVSS v3.1 base score of 7.5 (High) under NVD scoring, and 6.5 (Medium) under Elastic's own assessment (Elastic Advisory, Red Hat).

The root cause is Uncontrolled Resource Consumption (CWE-400) within Kibana's Timelion component, a time-series expression language and visualization engine. An attacker can craft malicious input data submitted to the Timelion component that causes the server to consume excessive CPU or memory resources, consistent with attack patterns such as Regular Expression Exponential Blowup (CAPEC-492) and XML Ping of the Death (CAPEC-147). Exploitation requires network access to the Kibana instance and low-level authentication privileges, with no user interaction needed (Elastic Advisory, Red Hat).

Successful exploitation results in a Denial of Service condition, rendering the Kibana service unavailable to legitimate users. The impact is limited to availability — there is no confidentiality or integrity impact, and the scope is unchanged (the vulnerability does not enable lateral movement or data exfiltration). Organizations relying on Kibana for security monitoring, log analysis, or operational dashboards may experience significant disruption during an attack (Elastic Advisory).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation as of the time of reporting (Elastic Advisory). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.039%, indicating a low probability of exploitation in the near term. Exploitation requires low-privilege authentication, which somewhat limits the attack surface compared to fully unauthenticated vulnerabilities.

1. Reconnaissance: Identify Kibana instances running versions 8.0.0–8.19.10 or 9.0.0–9.2.4 exposed on the network, using tools like Shodan or internal network scanning.
2. Authentication: Obtain low-privilege credentials to authenticate to the Kibana instance (e.g., a standard user account).
3. Craft malicious Timelion input: Construct a specially crafted Timelion expression or input payload designed to trigger excessive resource consumption (e.g., a deeply nested or exponentially expanding expression).
4. Submit payload: Send the malicious input to the Timelion component via the Kibana web interface or API endpoint.
5. Trigger DoS: The server processes the malicious input, consuming excessive CPU or memory, causing the Kibana service to become unresponsive or crash, resulting in a Denial of Service condition (Elastic Advisory).

• Logs: Kibana server logs showing repeated or sustained requests to Timelion-related API endpoints (e.g., /api/timelion/run) from a single or small set of source IPs; error logs indicating out-of-memory or timeout conditions.
• System: Sudden spikes in CPU or memory utilization on the Kibana host process (node or kibana) without a corresponding increase in legitimate user activity.
• Network: Unusual volume of authenticated POST requests to Timelion endpoints, particularly with large or complex payload bodies.
• Process: Kibana process becoming unresponsive, restarting unexpectedly, or triggering OOM (out-of-memory) killer events on the host system.

Elastic has released patched versions addressing this vulnerability: Kibana 8.19.11 and Kibana 9.2.5 (and later). Users should upgrade to one of these versions as the primary remediation (Elastic Advisory). As interim mitigations, organizations should implement network access controls to restrict Kibana access to authorized users only, and monitor instances for unusual resource consumption patterns. Limiting the privileges of Kibana user accounts and enforcing rate limiting on API endpoints can also reduce exposure.

Wuerth IT's NetEye blog published a security advisory in March 2026 covering this and related Elastic Stack vulnerabilities, indicating awareness within the managed security and monitoring community (NetEye Blog). Red Hat also tracked the vulnerability for potential impact on its products (Red Hat). No significant social media controversy or high-profile researcher commentary has been observed, consistent with the moderate severity and lack of public exploitation.