CVE-2026-21723
Received Received - Intake

Memory Exhaustion in Grafana Alertmanager Templates Test Endpoint

Publication date: 2026-07-23

Last updated on: 2026-07-23

Assigner: Grafana Labs

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 Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-07-23
Last Modified
2026-07-23
Generated
2026-07-23
AI Q&A
2026-07-23
EPSS Evaluated
N/A
NVD
CVE-2026-21723
EUVD
EUVD-2026-47869

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
grafana grafana *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability involves the Alertmanager templates test endpoint in Grafana. The endpoint can execute templates without memory limits, leading to out-of-memory (OOM) conditions when many templates are run quickly. This crashes the Grafana service. The endpoint requires low privileges and is accessible even with anonymous access enabled.

Detection Guidance

Check if the vulnerable endpoint /api/alertmanager/grafana/config/api/v1/templates/test is accessible. Use curl to test: curl -v http://<target>/api/alertmanager/grafana/config/api/v1/templates/test. Monitor for high memory usage or Grafana service crashes.

Impact Analysis

An attacker could exploit this to cause a denial-of-service by crashing Grafana through excessive template execution. This disrupts monitoring and alerting services, potentially leading to unnoticed system failures or downtime.

Compliance Impact

This vulnerability does not directly impact compliance with GDPR or HIPAA as it primarily causes service disruption through resource exhaustion rather than unauthorized data access or disclosure. However, repeated crashes could lead to downtime, potentially affecting availability requirements under these standards.

Mitigation Strategies

Disable anonymous access if enabled. Restrict access to the vulnerable endpoint via network policies or authentication. Update Grafana to the latest version once a patch is released.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-21723. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart