CVE-2026-81843: Memory exhaustion denial of service in Elasticsearch data source index patterns
Grafana is an open-source platform for monitoring and observability.
When an Elasticsearch data source is configured with a time-based index pattern, Grafana generated one index name for every interval in the requested query time range without any upper limit. A user with permission to query the data source, which includes users holding only the Viewer role in a default configuration, could submit a single small query with an extreme time range and cause the server to allocate memory until it was terminated. The allocation occurred before any request was sent to Elasticsearch, so the condition applied whether or not the Elasticsearch cluster was reachable.
Data sources configured with a static index name are not affected.
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Configure the Elasticsearch data source with a static index name; data sources using a static index name are not affected.
Grafana Elasticsearch data source index pattern = static index name
Event History
Frequently Asked Questions
Who can trigger the denial of service in a default deployment?
Any user permitted to query the affected Elasticsearch data source can trigger it. In the default configuration, this includes users with the Viewer role.
Which Elasticsearch data source configurations are affected?
Only data sources configured with a time-based index pattern are affected. Data sources using a static index name are not affected.
Does Elasticsearch need to be reachable for exploitation to work?
No. Grafana performs the unbounded index-name allocation before sending a request to Elasticsearch, so an unreachable cluster does not prevent the condition.
What kind of request triggers the issue?
A permitted user can submit a single small query with an extreme time range. Grafana generates an index name for every interval in that range until memory exhaustion can terminate the server.