CVE-2026-19516 in mcp-grafana
Summary
by MITRE • 08/11/2026
A caller-supplied X-Grafana-URL request header controls the destination of mcp-grafana's outbound requests, and the grafana_api_request tool lets the caller also choose the HTTP method, path, and body. Because the destination is not restricted to the configured Grafana instance, a caller can direct requests at internal, loopback, and link-local network services (including metadata endpoints) and read the responses, resulting in server-side request forgery. The fix for CVE-2026-15583 prevented the configured service-account token from being sent to unintended destinations but did not restrict the destinations themselves.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical server-side request forgery (SSRF) flaw in mcp-grafana's grafana_api_request tool that stems from inadequate input validation and destination control within the X-Grafana-URL request header mechanism. The vulnerability allows malicious actors to manipulate outbound requests by specifying arbitrary destinations through the caller-supplied header, bypassing intended security boundaries that should restrict communications to only the configured Grafana instance. The flaw operates at the application layer and exploits the trust relationship between components, enabling attackers to probe internal network services including loopback addresses, link-local networks, and metadata endpoints that are typically protected from external access.
The technical implementation of this vulnerability leverages the fact that the X-Grafana-URL header directly controls where outbound requests are directed without proper sanitization or destination validation. Combined with the grafana_api_request tool's ability to specify HTTP methods, paths, and request bodies, attackers can construct sophisticated attacks that traverse internal network boundaries. This creates a pathway for information disclosure through metadata endpoints such as AWS metadata services, Azure Instance Metadata Service, or similar internal APIs that contain sensitive configuration data, credentials, or system information. The vulnerability is classified under CWE-918 Server-Side Request Forgery and aligns with ATT&CK technique T1566.002 Phishing via Service Provider, as it enables attackers to abuse legitimate service accounts for unauthorized network reconnaissance.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable further attack vectors including privilege escalation through credential harvesting from metadata services. Attackers can leverage the service account token that was previously not restricted to unintended destinations, but now they can also control the actual target of these requests, amplifying the potential damage significantly. The vulnerability affects environments where mcp-grafana operates in network segments with access to internal services or where metadata endpoints are exposed, making it particularly dangerous in cloud environments or containerized deployments where such endpoints are commonly accessible. Organizations using this tool without proper network segmentation or firewall rules may find their internal infrastructure exposed to unauthorized reconnaissance and data extraction.
Mitigation strategies should focus on implementing strict destination validation and restricting outbound request capabilities to only trusted endpoints within the configured Grafana instance. The fix for CVE-2026-15583 addressed token transmission but failed to properly restrict destinations, highlighting the need for comprehensive input validation at multiple layers. Organizations should implement network-level controls using firewalls or network segmentation to prevent access to internal services from the mcp-grafana component. Additionally, implementing proper header sanitization, destination whitelisting, and mandatory configuration validation can prevent similar vulnerabilities. The solution must ensure that any outbound requests are restricted to pre-approved domains or IP ranges, and service accounts should only be able to communicate with intended targets as defined in the system configuration rather than allowing arbitrary destination specification through request headers.