Security Advisory

CVE-2026-21723

5.3
MEDIUM

Vulnerability Description

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.
Published Date July 23, 2026
Official Source NIST NVD Advisory