CVE-2026-8609

A flaw was found in Grafana. An unauthenticated attacker can repeatedly access the OAuth login route with unique values. This can lead to unbounded memory growth, eventually exhausting system memory and causing the Grafana instance to crash. This results in a denial of service for legitimate users.

The flaw in Grafana is rated Moderate, as an unauthenticated attacker can trigger a denial of service by repeatedly accessing the OAuth login route, leading to unbounded memory growth and instance crashes.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, restrict network access to the Grafana instance to trusted internal networks or localhost. If a reverse proxy or load balancer is deployed in front of Grafana, configure it to implement rate limiting on requests to the OAuth login endpoint to prevent an attacker from exhausting system resources. If OAuth is not required, consider disabling it in the Grafana configuration, though this may impact user authentication workflows.