Is CVE-2026-21723 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-21723?

CVE-2026-21723 has a CVSS v3 severity of MEDIUM (5.3).

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CVE-2026-21723

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.