CVE-2021-39226 is an authentication bypass vulnerability in Grafana Labs Grafana. CISA added it to the Known Exploited Vulnerabilities catalogue on 25 August 2022, which means attackers have used it in real attacks. Grafana contains an authentication bypass vulnerability that allows authenticated and unauthenticated users to view and delete all snapshot data, potentially resulting in complete snapshot data loss.
What this vulnerability means in Grafana
This CVE is dangerous because it breaks a core trust boundary in Grafana, allowing access to snapshot data without the expected authentication checks. When an attacker can reach snapshot content through an authentication bypass, the issue is not just unauthorized viewing, it is also the potential destruction of shared operational data that teams may assume is safely controlled.
For readers who want the authoritative record of the vulnerability itself, the CVE Program and NIST National Vulnerability Database remain the canonical places to confirm the record and track advisory details.
Why authentication bypasses are high impact
An authentication bypass changes the security model of the product, because controls that normally separate anonymous, authenticated, and privileged actions no longer behave as intended. In a dashboarding or observability platform, that can expose operational evidence, configuration context, and saved artifacts to anyone who can reach the vulnerable endpoint.
The danger is amplified when the affected function includes deletion. If snapshots can be removed without proper authorization, the issue becomes both confidentiality and integrity related, since defenders may lose the ability to review historical state, share evidence, or recover information needed for incident analysis.
Internal guidance on vulnerability management is useful here because exposure assessment should start with asset inventory, internet-facing services, and whether the product instance is reachable from untrusted networks.
How organisations should assess exposure
Exposure checks for a CVE like this should focus on where Grafana is deployed, who can reach it, and whether the vulnerable function is enabled or operationally important. Organisations should also review vendor advisories and the CISA Known Exploited Vulnerabilities catalogue rather than relying on general assumptions about version age or patch status.
Because this issue is in a widely used administrative platform, the practical question is often not whether Grafana exists somewhere in the environment, but whether exposed instances are serving production teams, external users, or shared operational workspaces. A forgotten instance can still be a viable entry point for data loss or reconnaissance.
The NIST SP 800-63 Digital Identity Guidelines are a useful external reference for understanding strong authentication expectations, especially when organisations are deciding how much trust to place in sign-in flows that gate administrative or data-management functions.
Remediation, detection, and recovery after exploitation
The most important response is to apply the vendor fix as soon as the approved version path is available, then verify that the vulnerable behaviour is no longer reachable. Where patching is delayed, organisations should reduce exposure by restricting network access, segmenting administrative interfaces, and limiting who can reach snapshot-related functions.
After remediation, teams should review logs for unusual snapshot access, deletion activity, and any administrative actions that occurred during the exposure window. If exploitation is suspected, treat affected accounts, sessions, and any related API credentials as potentially exposed until review is complete.
For operational follow-up, the Vulnerability Management Guide is a practical companion for prioritisation, verification, and exception handling, while Change Healthcare breach 2024 is a reminder that a single exposed access path can cascade into major operational harm when remote access or application controls fail.
Risk and Threat Considerations
Authentication bypasses are attractive because they let an attacker skip the normal trust checks that protect data and administrative functions. In this case, the likely outcome is not just unauthorized access, but destructive abuse of snapshot data that can undermine investigation, continuity, and confidence in the platform.
Failure mechanism: The product accepts requests that should require valid authentication or authorization, allowing a remote actor to reach snapshot functions and perform actions the interface should have blocked.
Impact: Attackers may view or delete snapshot data, causing data exposure, loss of historical evidence, and potential disruption to operational or forensic workflows.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
NIST SP 800-53 Rev 5 sets the technical controls, while ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | IA-2 — Identification and Authentication (Organizational Users) | Grafana login bypass directly weakens user authentication controls. |
| AC-6 — Least Privilege | Snapshot viewing and deletion should be limited to narrowly authorised users. | |
| AU-2 — Audit Events | Snapshot access and deletion are material events that need reviewable logging. | |
| Recommendation — Enforce IA-2 protections on Grafana access paths and verify that authentication cannot be bypassed. Apply AC-6 so only approved roles can view or delete Grafana snapshots. Log Grafana snapshot access and deletion events for detection and investigation. | ||
| ISO/IEC 27001:2022 | A.8.5 — Secure authentication | This CVE is an authentication bypass, so authentication design and control matter directly. |
| Recommendation — Review Grafana authentication design and confirm bypass paths are removed or blocked. | ||
Practitioner Guidance
Why practitioners should care: Authentication bypass issues in operational platforms often become urgent because they affect both day-to-day service use and incident response evidence. Teams should treat exposed admin or snapshot functions as high-value paths, not cosmetic interface issues.
What to watch for: Unexpected snapshot deletion, strange access patterns from low-trust networks, and any sign that a Grafana instance is reachable beyond the audience it was meant to serve. If those signals appear, assume the trust boundary has already failed and investigate the surrounding account and network conditions.
Related resources from NHI Mgmt Group
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Reviewed and updated by the NHIMG editorial team on October 17, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org