CVE-2026-21723 — MEDIUM (5.3)

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.

CVSS Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Related Weaknesses (CWE)

CWE-400

References

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

FAQ

What is CVE-2026-21723?

CVE-2026-21723 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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...

How severe is CVE-2026-21723?

CVE-2026-21723 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-21723?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.