DoS Vulnerability in Templates Test endpoint
Medium
- Advisory ID:
- CVE-2026-21723
- Published:
- 2026-07-22
- Product:
- Grafana
- CVSS Score:
- 5.3
- CVSS Vector:
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- Fixed Versions:
- >=11.6.11>=12.0.10>=12.1.7>=12.2.5>=12.3.3
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.
Thanks to the researcher nacl for this report!