CVE-2026-9703
published 2026-10-15CVE-2026-9703: 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…
PriorityP344high7.1CVSS 3.1
AVNACLPRLUINSUCNIHAL
EPSS
0.19%
8.5th percentile
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.
Affected
11 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| grafana | grafana_enterprise | 11.6.0 – 11.6.16 | — |
| grafana | grafana_enterprise | 12.0.0 – 12.1.10 | — |
| grafana | grafana_enterprise | 12.2.0 – 12.2.10 | — |
| grafana | grafana_enterprise | 12.3.0 – 12.3.8 | — |
| grafana | grafana_enterprise | 12.4.0 – 12.4.5 | — |
| grafana | grafana_enterprise | 13.0.0 – 13.0.3 | — |
| grafana | grafana_enterprise | 8.0.0 – 11.5.10 | — |
| grafana | grafana_oss | 12.3.0 – 12.3.8 | — |
| grafana | grafana_oss | 12.4.0 – 12.4.5 | — |
| grafana | grafana_oss | 13.0.0 – 13.0.3 | — |
| grafana | grafana_oss | 8.0.0 – 12.3.0 | — |
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VulDB
Grafana Data Source Proxy /loki/api/v1/rules access control (WID-SEC-2026-4002)
vuldb·2026-10-16·CVSS 7.1
CVE-2026-9703 [HIGH] Grafana Data Source Proxy /loki/api/v1/rules access control (WID-SEC-2026-4002)
A vulnerability was found in Grafana. It has been declared as problematic. Affected is an unknown function of the file /loki/api/v1/rules of the component Data Source Proxy. Such manipulation leads to improper access controls.
This vulnerability is referenced as CVE-2026-9703. It is possible to launch the attack remotely. No exploit is available.
GHSA
Grafana's data source proxy did not apply role-based access control to write requests forwarded to Loki data sources.
ghsa_unreviewed·2026-10-15
CVE-2026-9703 [HIGH] CWE-284 Grafana's data source proxy did not apply role-based access control to write requests forwarded to Loki data sources.
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 vulnerabl
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-10-15
Published