CVE-2026-42399: Uncontrolled Resource Consumption in Kibana Leading to Denial of Service
Uncontrolled Resource Consumption (CWE-400) in Kibana can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated low-privileged user can cause Kibana to consume exponentially increasing amounts of memory by submitting a specially crafted Timelion visualization expression containing deeply chained function calls. The resulting data structure grows without bound, exhausting available memory and causing the Kibana service to crash and become unavailable to all users.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Remove
Remove
Kibana/Timelionfrom your environment.Uninstall or remove the Timelion module/plugin if it is not required to eliminate the attack surface for specially crafted Timelion expressions.
- Configuration
Disable the Timelion visualization feature to prevent processing of user-submitted Timelion expressions that can cause unbounded memory growth.
Kibana (Timelion) enabled = false - Configuration
Restrict creation of Timelion visualizations (and visualization creation in general) to trusted administrator roles; remove or limit this capability for low-privileged users.
Kibana ability to create visualizations = restricted to trusted/administrator roles - Compensating control
Restrict access to the Kibana UI to trusted IP ranges or internal networks at the firewall/perimeter to reduce exposure to authenticated low-privileged users who could submit malicious Timelion expressions.
- Compensating control
Implement request rate-limiting or request-size limits on endpoints that accept Timelion expressions or visualization submissions to reduce the risk of resource exhaustion.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42399?
The severity of CVE-2026-42399 is rated medium with a score of 6.5.
What does CVE-2026-42399 affect?
CVE-2026-42399 affects the Elastic Kibana software.
How can CVE-2026-42399 be exploited?
CVE-2026-42399 can be exploited by an authenticated low-privileged user submitting a specially crafted Timelion visualization expression.
What are the potential consequences of CVE-2026-42399?
CVE-2026-42399 can lead to denial of service due to uncontrolled resource consumption.
How do I fix CVE-2026-42399?
To fix CVE-2026-42399, update to the latest version of Kibana provided by Elastic.