CVE-2026-42399 Uncontrolled Resource Consumption in Kibana Leading to Denial of Service
An authenticated low-privileged user can crash Kibana by submitting a crafted Timelion expression that causes excessive memory consumption.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42399?
CVE-2026-42399 is a medium-severity denial of service vulnerability in Elastic Kibana, published on 28 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-400
Which versions are affected by CVE-2026-42399?
2 open source packages ship an affected version, including kibana and elk. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
kibana Bitnami | From 8.0.0 | 8.19.16, 9.3.5 |
elk Bitnami | From 8.0.0 | 8.19.16, 9.3.5 |
Products include Elastic Kibana.
How do I fix CVE-2026-42399?
Upgrade kibana to a fixed version for your release line: 8.19.16 or 9.3.5.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-42399 being exploited?
There is no known exploitation of CVE-2026-42399 in the wild and no public exploit code.
Other vulnerabilities in Elastic Kibana
Sources
Also known as BIT-elk-2026-42399, BIT-kibana-2026-42399, GHSA-hcw2-vpp7-52v9, MINI-7mr6-865c-p2j2, MINI-gpc9-9hqp-g2qp, MINI-h387-chfw-6vhj and 3 more.