CVE-2026-9703 Grafana CVE debrief

Who should care

Grafana administrators, security teams, and users with the Viewer role on affected instances should assess exposure and take defensive actions. This includes verifying Grafana instance exposure, reviewing access controls for the Viewer role, and monitoring for suspicious Loki alerting rule changes. Additionally, defenders should prioritize verifying exposure of Grafana instances, especially those with Loki data sources configured, and review access

Why it matters

This vulnerability allows a user with the Viewer role to manipulate Loki alerting rules, potentially affecting all users of the Loki data source. Defenders should verify exposure, review access controls, and monitor for suspicious activity.

• Verify exposure of Grafana instances with Loki data sources
• Restrict Viewer role access to Loki rules API
• Monitor for suspicious Loki alerting rule changes

Technical summary

The Grafana data source proxy does not apply role-based access control to write requests forwarded to Loki data sources, allowing a user with the Viewer role to create, modify, and delete Loki alerting rules. This issue affects both Grafana OSS and Grafana Enterprise instances. Exploitation requires an authenticated Viewer account on the Grafana instance and a configured Loki data source. The vulnerability is stored by Loki rather than by Grafana, so changes take effect for every user of that Loki data source, not only for the Viewer who made the request.

Defensive priority

Defenders should prioritize verifying exposure of Grafana instances, especially those with Loki data sources configured, and review access controls for the Viewer role.

Recommended defensive actions

• Verify Grafana instance exposure and Loki data source configuration
• Review and restrict Viewer role access to Loki rules API
• Monitor for suspicious Loki alerting rule changes
• Apply vendor-provided patches or updates
• Track exceptions and retest remediated assets
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, affected versions, and references to vendor advisories. The Grafana data source proxy does not apply role-based access control to write requests forwarded to Loki data sources, allowing a user with the Viewer role to create, modify, and delete Loki alerting rules. There are no details on publicly available exploits or reports of exploitation. Vendor advisories and patches should be consulted for specific guidance on affected versions and mitigation steps. The CVE

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.