CVE-2026-8609 in Grafana
Summary
by MITRE • 07/10/2026
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).
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Analysis
by VulDB Data Team • 07/10/2026
This vulnerability represents a critical denial of service condition within Grafana's authentication infrastructure that exploits improper handling of OAuth login requests. The flaw manifests when an unauthenticated attacker repeatedly invokes the OAuth login endpoint with varying parameters, leading to continuous memory allocation without adequate cleanup mechanisms. This behavior creates a memory leak scenario where each successful request contributes to progressive heap consumption, ultimately resulting in system resource exhaustion and complete service disruption.
The technical implementation reveals a fundamental weakness in Grafana's session management and parameter validation processes during OAuth authentication flows. When the system receives repeated login attempts with unique identifiers, it fails to properly terminate or recycle temporary objects created for each authentication attempt. This creates a pathological condition where memory allocated for tracking these requests grows without bounds, typically through accumulation of session tokens, request contexts, or caching structures that should be automatically purged after successful authentication or timeout periods.
From an operational perspective this vulnerability poses significant risks to Grafana deployments across various threat scenarios including automated scanning campaigns, brute force attacks, or simple resource exhaustion attempts. The impact extends beyond immediate service disruption to potentially affect system stability and availability of monitoring infrastructure that organizations rely upon for critical operations. Organizations with high-traffic Grafana instances face heightened risk as the memory consumption accelerates more rapidly under load conditions, making this vulnerability particularly dangerous in production environments.
The vulnerability can be mapped to CWE-400 which specifically addresses "Uncontrolled Resource Consumption" and aligns with ATT&CK technique T1499.1 for "Application Exhaustion Flood" within the resource exhaustion category. This classification indicates that attackers can leverage the flaw to consume system resources through legitimate application functionality, making detection more challenging as the behavior appears normal from an external perspective. Mitigation strategies should include implementing rate limiting on authentication endpoints, establishing memory consumption thresholds with automatic restart mechanisms, and configuring proper session cleanup routines that prevent accumulation of stale objects.
Security practitioners should prioritize immediate patching of affected Grafana versions while implementing monitoring for unusual memory usage patterns in authentication components. Network-level controls such as IP-based rate limiting and authentication request throttling can provide additional defense-in-depth measures. The vulnerability highlights the importance of proper resource management in web applications, particularly those handling authentication flows where temporary state objects must be carefully managed to prevent accumulation over time. Organizations should conduct thorough testing of their monitoring systems to ensure early detection of memory exhaustion patterns that could indicate exploitation attempts against this vulnerability.