CVE-2026-21722 is a vulnerability identified in the Grafana open-source analytics and monitoring platform, specifically affecting versions 9.3.0, 12.0.0, 12.2.0, and 12.3.0. The issue arises when public dashboards have annotations enabled. Normally, a public dashboard can be configured with a locked timerange, restricting the visible data and annotations to a specific time window. However, due to improper enforcement of this restriction, the annotation timerange was not limited to the locked timerange, allowing an attacker to access the full history of annotations visible on that dashboard, including those outside the locked timerange. Importantly, the vulnerability does not expose annotations that are not already visible on the public dashboard, so it does not expand the scope of accessible data beyond what the dashboard permits. The vulnerability is classified under CWE-863 (Incorrect Authorization), indicating a failure to properly enforce access control policies. The CVSS v3.1 base score is 5.3 (medium severity), reflecting that the vulnerability can be exploited remotely without authentication or user interaction, with a limited confidentiality impact and no effect on integrity or availability. No patches were linked in the provided data, and no known exploits have been reported in the wild as of the publication date. This vulnerability could be exploited by an attacker simply by accessing the public dashboard URL and manipulating annotation queries to retrieve annotations outside the locked timerange, potentially revealing sensitive historical annotation data that was intended to be restricted.

The primary impact of CVE-2026-21722 is a confidentiality breach where an attacker can access annotation data outside the intended locked timerange on public Grafana dashboards. While the annotations are limited to those already visible on the public dashboard, the exposure of historical annotations beyond the locked timerange could reveal sensitive operational or monitoring insights that organizations prefer to restrict. This could lead to information disclosure about system events, incidents, or performance trends that might aid attackers in reconnaissance or social engineering. Since the vulnerability does not affect data integrity or availability, the risk is confined to unauthorized data disclosure. Organizations relying on Grafana for monitoring critical infrastructure, cloud services, or internal systems with public dashboards are at risk of leaking sensitive annotation metadata. The ease of exploitation (no authentication or user interaction required) increases the likelihood of opportunistic attacks, especially if dashboards are widely accessible. However, the absence of known exploits in the wild suggests limited active exploitation currently. The impact is more significant for organizations that expose detailed annotations publicly and rely on locked timeranges to control data visibility.

To mitigate CVE-2026-21722, organizations should take the following specific actions: 1) Upgrade Grafana to a version where this vulnerability is fixed once a patch is released; monitor Grafana's official channels for patch announcements. 2) Until patched, review all public dashboards with annotations enabled and locked timeranges; consider disabling annotations on public dashboards or removing public access if annotations are critical. 3) Implement network-level access controls or authentication gateways to restrict access to sensitive dashboards, reducing exposure to unauthorized users. 4) Audit existing annotations and timerange configurations to ensure no sensitive information is unintentionally exposed beyond intended time windows. 5) Monitor access logs for unusual or automated requests targeting annotations on public dashboards, which may indicate exploitation attempts. 6) Educate dashboard creators and administrators on the risks of exposing annotations publicly and enforce policies limiting public dashboard configurations. 7) Consider using Grafana's role-based access control features to restrict annotation visibility more granularly. These steps go beyond generic advice by focusing on annotation-specific controls and temporary compensating controls until patches are available.