CVE-2026-26937 Overview
CVE-2026-26937 is an Uncontrolled Resource Consumption vulnerability (CWE-400) affecting the Timelion component in Kibana. This vulnerability enables authenticated attackers to trigger a Denial of Service condition through Input Data Manipulation (CAPEC-153). When exploited, malicious input can cause excessive resource consumption, potentially rendering the Kibana service unavailable to legitimate users.
Critical Impact
Authenticated attackers can exploit this vulnerability to cause service disruption in Kibana environments, affecting monitoring and analytics capabilities for organizations relying on the Elastic Stack.
Affected Products
- Kibana versions prior to 8.19.11
- Kibana versions prior to 9.2.5
Discovery Timeline
- 2026-02-26 - CVE CVE-2026-26937 published to NVD
- 2026-02-26 - Last updated in NVD database
Technical Details for CVE-2026-26937
Vulnerability Analysis
This vulnerability exists within the Timelion visualization component of Kibana. Timelion is a time series data visualizer that allows users to combine independent data sources using expressions. The flaw stems from inadequate input validation and resource management when processing user-supplied data through the Timelion expression language.
When a user with low privileges submits specially crafted input to the Timelion component, the application fails to properly limit resource consumption. This allows the attacker to exhaust server resources such as CPU cycles or memory, leading to service degradation or complete unavailability. The attack requires network access and valid authentication credentials, but does not require user interaction once the attacker is authenticated.
Root Cause
The root cause is Uncontrolled Resource Consumption (CWE-400) in Kibana's Timelion component. The vulnerability arises from insufficient validation and resource throttling when processing Timelion expressions. The component does not adequately constrain the computational complexity or memory allocation that can be triggered by maliciously crafted input data, allowing attackers to consume excessive server resources.
Attack Vector
The attack is conducted over the network by an authenticated user with low privileges. The attacker crafts malicious input data targeting the Timelion component's expression parser. When processed, this input triggers resource-intensive operations that can exhaust available system resources. The attack does not require any user interaction beyond the attacker's own authenticated session, and the impact is limited to availability—no confidentiality or integrity breach occurs.
The vulnerability can be exploited by submitting carefully constructed Timelion expressions through the Kibana web interface or API endpoints. These expressions may include deeply nested operations, recursive patterns, or computationally expensive queries that overwhelm the server's processing capacity.
Detection Methods for CVE-2026-26937
Indicators of Compromise
- Unusual spikes in CPU or memory utilization on Kibana servers
- Elevated number of requests to Timelion-related API endpoints from specific user accounts
- Kibana service becoming unresponsive or crashing unexpectedly
- Abnormal Timelion expression patterns in application logs
Detection Strategies
- Monitor Kibana server resource utilization for anomalous consumption patterns
- Implement rate limiting on Timelion API endpoints to detect and prevent abuse
- Review authentication logs for repeated access attempts to visualization components
- Configure alerting for Kibana service health metrics and availability
Monitoring Recommendations
- Enable detailed logging for Timelion component interactions
- Set up resource consumption thresholds and alerts on Kibana nodes
- Monitor for unusual query patterns or expression complexity in Timelion requests
- Correlate Kibana access logs with system performance metrics
How to Mitigate CVE-2026-26937
Immediate Actions Required
- Upgrade Kibana to version 8.19.11 or 9.2.5 or later immediately
- Review user access permissions and restrict Timelion access to trusted users only
- Implement network-level access controls to limit exposure of Kibana services
- Monitor Kibana server resources for signs of exploitation attempts
Patch Information
Elastic has released security updates addressing this vulnerability. Organizations should upgrade to Kibana version 8.19.11 or 9.2.5 or later, as detailed in the Elastic Security Update Advisory. The patch implements proper resource constraints and input validation for the Timelion component to prevent resource exhaustion attacks.
Workarounds
- Restrict access to the Timelion feature to only essential users pending patch deployment
- Implement application-level rate limiting for Timelion API endpoints
- Consider temporarily disabling Timelion if not critical to operations until the patch is applied
- Deploy network segmentation to limit exposure of Kibana services to trusted networks only
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
