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

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• grafana grafana11.6.0 and later · before 11.6.15
• grafana grafana12.2.0 and later · before 12.2.9
• grafana grafana12.3.0 and later · before 12.3.7
• grafana grafana12.4.0 and later · before 12.4.4
• grafana grafana13.0.0 and later · before 13.0.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GRAFANA). Independent of NVD's CPE analysis and usually ahead of it.

• Grafana Grafana OSS

  • 11.6.0 and later · up to and including 11.6.14affected · semver
  • 12.2.0 and later · up to and including 12.2.8affected · semver
  • 12.3.0 and later · up to and including 12.3.6affected · semver
  • 12.4.0 and later · up to and including 12.4.3affected · semver
  • 13.0.0 and later · up to and including 13.0.1affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Other highest-scoring records for the same primary product.

• CVE-2021-39226Snapshot authentication bypass in grafanaKEV
  89Now
• CVE-2021-43798Grafana path traversalKEV
  87Now
• CVE-2024-9264Grafana SQL Expressions allow for remote code execution
  66This week

Published before and after this one in the same product

• ← EarlierCVE-2026-33382Jul 10, 2026 · Denial of service via unbounded request body size
  30Monitor
• ← EarlierCVE-2026-8595Jul 10, 2026 · Stored XSS in the table panel (TableNG)
  21Monitor
• Later →CVE-2026-14199Sep 2, 2026 · Session takeover via Auth Proxy cache key collision
  32Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1function expand(node) {2  return node.children.map(expand);3}

1const MAX_DEPTH = 32;2function expand(node, depth = 0) {3  if (depth > MAX_DEPTH) throw new Error("too deep");4  return node.children.map((c) => expand(c, depth + 1));5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.