VulnerabilityDeferred

CVE-2026-21723

The alertmanager templates test endpoint (/api/alertmanager/grafana/config/api/v1/templates/test) can execute templates with no memory limits.

MEDIUM 5.3EPSS 0.33%

Does this matter?

Lower severity and a low EPSS score (0.33%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 5.3 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.33% probability · 26th percentile
CISA KEV: Not listed
Weakness: CWE-400
Source: security@grafana.com

References

https://grafana.com/security/security-advisories/cve-2026-21723

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.