CVE-2026-9703

Viewer role can create, modify and delete Loki alerting rules

HIGH

7.1

CVSS Score

Published: October 15, 2026 at 02:02 PM UTC

Updated: October 16, 2026 at 08:02 PM UTC

1 product affected across 1 vendorGrafana

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Severity

HIGH7.1

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

Description

Grafana's data source proxy did not apply role-based access control to write requests forwarded to Loki data sources. A user holding only the Viewer role on an affected Grafana instance could send POST, PUT and DELETE requests through the proxy to the Loki rules API (/loki/api/v1/rules), allowing them to create, modify and delete Loki alerting rules. Because those rules are stored by Loki rather than by Grafana, the change took effect for every user of that Loki data source, not only for the Viewer who made the request. Exploitation requires an authenticated Viewer account on the Grafana instance and a configured Loki data source; no other privileges are needed. Both Grafana OSS and Grafana Enterprise are affected. The defect is in Grafana's data source proxy; Loki itself is not vulnerable and does not need to be patched.