CVE-2026-28379 Overview
CVE-2026-28379 is a race condition vulnerability in Grafana Live that authenticated users can exploit to crash the Grafana server. The flaw resides in Grafana's real-time streaming component and is triggered when concurrent requests cause a fatal map access error in the underlying Go runtime. Any authenticated account, including low-privilege Viewer roles, can submit the malicious request pattern. Successful exploitation results in complete service unavailability and requires a manual restart of the Grafana server to restore monitoring functionality.
Critical Impact
Authenticated Viewer-role users can crash the Grafana server remotely with concurrent requests, taking observability services offline until manually restarted.
Affected Products
- Grafana (Grafana Live component)
- See the Grafana Security Advisory CVE-2026-28379 for the affected version ranges
Discovery Timeline
- 2026-05-13 - CVE-2026-28379 published to the National Vulnerability Database (NVD)
- 2026-05-13 - Last updated in NVD database
Technical Details for CVE-2026-28379
Vulnerability Analysis
Grafana Live is the websocket-based component that streams real-time data to dashboards and panels. The vulnerability is a race condition in concurrent map access within this component. When multiple requests arrive simultaneously, unsynchronized read and write operations on a shared map trigger a fatal runtime error in Go. Go's runtime treats concurrent map writes as unrecoverable and terminates the process. The result is a full denial-of-service condition affecting all dashboards, alerts, and data sources served by the affected instance.
Root Cause
The root cause is missing synchronization on a shared in-memory map used by Grafana Live to track session or channel state. Without a mutex or sync.Map, parallel goroutines handling concurrent client requests race on the same map structure. Go's runtime detects the unsafe access pattern and aborts the process with a fatal error rather than continuing in an undefined state. This is a classic [CWE-362] concurrent execution flaw escalating into a [CWE-400] uncontrolled resource consumption outcome.
Attack Vector
The attack vector is network-based and requires only a valid authenticated session with the lowest available role, Viewer. An attacker scripts a small number of concurrent requests to a Grafana Live endpoint within the same process window. No user interaction is needed beyond initial authentication. Because Viewer-level credentials are often issued broadly across organizations, the practical exploitation barrier is low. The vulnerability does not expose data confidentiality or integrity, but the availability impact is high. Refer to the Grafana Security Advisory CVE-2026-28379 for endpoint-specific technical details.
Detection Methods for CVE-2026-28379
Indicators of Compromise
- Grafana process termination accompanied by fatal error: concurrent map read and map write or concurrent map writes messages in service logs
- Multiple near-simultaneous requests to Grafana Live websocket or HTTP streaming endpoints from a single authenticated session
- Unexpected Grafana service restarts logged by the init system (systemd, container orchestrator) without administrator action
Detection Strategies
- Monitor Grafana stderr and journal output for Go runtime fatal errors referencing map access
- Alert on Grafana process exit codes inconsistent with normal shutdown sequences
- Baseline normal request rates to Live endpoints and flag bursts of concurrent connections from individual user tokens
Monitoring Recommendations
- Forward Grafana application logs and host service-manager events to a centralized SIEM for correlation
- Track authenticated API and websocket request counts per user identifier to surface abusive Viewer accounts
- Configure uptime monitoring on Grafana's /api/health endpoint to detect crash-and-restart cycles
How to Mitigate CVE-2026-28379
Immediate Actions Required
- Upgrade Grafana to the fixed version identified in the Grafana Security Advisory CVE-2026-28379
- Audit Viewer-role accounts and revoke unused or shared credentials that could be abused for denial-of-service
- Place Grafana behind a reverse proxy with per-user rate limiting on Live endpoints until patching is complete
Patch Information
Grafana Labs has published remediation guidance and fixed versions in the Grafana Security Advisory CVE-2026-28379. Administrators should apply the vendor patch as the primary mitigation. Self-hosted deployments must update binaries or container images, while Grafana Cloud tenants receive fixes through the managed service.
Workarounds
- Disable Grafana Live in grafana.ini by setting [live] max_connections = 0 if streaming features are not in use
- Restrict access to Grafana Live endpoints at the network layer to trusted client ranges only
- Enforce stricter authentication policies and reduce the number of Viewer accounts pending the upgrade
# Configuration example: disable Grafana Live as a temporary workaround
# /etc/grafana/grafana.ini
[live]
max_connections = 0
# Restart Grafana to apply the change
sudo systemctl restart grafana-server
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
