CVE-2026-21723

Summary

The alertmanager templates test endpoint (/api/alertmanager/grafana/config/api/v1/templates/test) can execute templates with no memory limits. Mass-executing templates in a short period causes OOM and crashes the Grafana service. The endpoint requires very low privileges and is exploitable with anonymous access enabled.

Affected Software

VendorProductVersion RangeStatus
GrafanaGrafana OSS8.0.0 <= 11.0.0affected
GrafanaGrafana OSS11.0.0 <= 11.6.10affected
GrafanaGrafana OSS12.0.0 <= 12.0.9affected
GrafanaGrafana OSS12.1.0 <= 12.1.6affected
GrafanaGrafana OSS12.2.0 <= 12.2.4affected
GrafanaGrafana OSS12.3.0 <= 12.3.2affected

Weaknesses

References