CVE-2026-28375 Overview
CVE-2026-28375 is a Denial of Service vulnerability affecting Grafana, the popular open-source analytics and monitoring platform. The vulnerability exists in the testdata data-source functionality, which can be exploited by authenticated users to trigger out-of-memory crashes, causing service disruption for all users of the affected Grafana instance.
Critical Impact
Authenticated attackers can crash Grafana instances by exploiting the testdata data-source to consume excessive memory, resulting in denial of service conditions that affect monitoring and observability capabilities.
Affected Products
- Grafana (multiple versions)
- Grafana Enterprise (multiple versions)
- Self-hosted and cloud-managed Grafana deployments
Discovery Timeline
- 2026-03-27 - CVE-2026-28375 published to NVD
- 2026-03-31 - Last updated in NVD database
Technical Details for CVE-2026-28375
Vulnerability Analysis
This vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption), which occurs when an application does not properly restrict the amount of resources that can be requested or consumed by an actor. In this case, the testdata data-source in Grafana lacks appropriate bounds checking on memory allocation, allowing malicious requests to exhaust available system memory.
The testdata data-source is a built-in feature in Grafana primarily intended for testing and development purposes. It allows users to generate synthetic data for dashboards without connecting to external data sources. However, the vulnerability allows specially crafted requests to this data-source to allocate unbounded amounts of memory, leading to out-of-memory (OOM) conditions.
Root Cause
The root cause of this vulnerability lies in insufficient input validation and resource limitation controls within the testdata data-source handler. When processing requests to generate test data, the application fails to enforce reasonable limits on the size or quantity of data that can be requested. This allows an attacker to specify parameters that result in excessive memory allocation, ultimately exhausting available system resources.
The absence of proper resource quotas means that even a single malicious request can consume enough memory to crash the entire Grafana process, affecting all users and dashboards relying on that instance.
Attack Vector
The attack is network-based and requires low-level authentication (any authenticated Grafana user can potentially exploit this vulnerability). The attacker must have access to query the testdata data-source, which is enabled by default in many Grafana installations.
The exploitation flow involves:
- Authenticating to the target Grafana instance with any valid user credentials
- Crafting a malicious query to the testdata data-source with parameters designed to trigger excessive memory allocation
- Submitting the query, which causes the Grafana server to allocate unbounded memory
- The server experiences an out-of-memory condition and crashes, denying service to all users
Since no code examples are available from verified sources, the technical specifics of the payload construction should be referenced from the Grafana Security Advisory CVE-2026-28375.
Detection Methods for CVE-2026-28375
Indicators of Compromise
- Sudden spikes in memory consumption on Grafana server processes
- Grafana service crashes or restarts without apparent cause
- Error logs indicating out-of-memory conditions or allocation failures
- Unusual query patterns targeting the testdata data-source
Detection Strategies
- Monitor Grafana process memory usage for abnormal growth patterns
- Implement alerting on Grafana service availability and restart events
- Review access logs for suspicious queries to the testdata data-source endpoint
- Deploy application performance monitoring (APM) to track resource consumption per request
Monitoring Recommendations
- Configure resource usage alerts with thresholds appropriate for your environment
- Enable detailed query logging to capture testdata data-source requests
- Implement service health checks that detect and alert on OOM-related restarts
- Use container resource limits if running Grafana in containerized environments
How to Mitigate CVE-2026-28375
Immediate Actions Required
- Apply the latest Grafana security patches as specified in the vendor advisory
- Consider disabling the testdata data-source if not required in production environments
- Implement container or process-level memory limits to prevent full system crashes
- Review and restrict user permissions to limit access to data-source configuration
Patch Information
Grafana has released security patches addressing this vulnerability. Organizations should consult the Grafana Security Advisory CVE-2026-28375 for specific version information and upgrade instructions. Ensure you upgrade to the latest patched version appropriate for your deployment.
Workarounds
- Disable the testdata data-source in production environments where it is not needed
- Implement network-level access controls to restrict who can query Grafana APIs
- Configure memory limits at the container or system level to contain the blast radius
- Use a Web Application Firewall (WAF) to rate-limit or block suspicious query patterns
# Example: Disable testdata data-source via Grafana configuration
# Add to grafana.ini or environment variables
[plugins]
# Disable testdata plugin to prevent exploitation
disable_plugins = testdata
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
