Grafana Alertmanager Templates OOM via Unlimited Exec
CVE-2026-21723 Published on July 23, 2026
CVE-2026-21723 Record
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.
Weakness Type
What is a Resource Exhaustion Vulnerability?
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
CVE-2026-21723 has been classified to as a Resource Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-21723
Want to know whenever a new CVE is published for Grafana Labs Grafana? stack.watch will email you.
Affected Versions
Grafana OSS:- Version 8.0.0, <= 11.0.0 is affected.
- Version 11.0.0, <= 11.6.10 is affected.
- Version 12.0.0, <= 12.0.9 is affected.
- Version 12.1.0, <= 12.1.6 is affected.
- Version 12.2.0, <= 12.2.4 is affected.
- Version 12.3.0, <= 12.3.2 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.