## Summary
CVE-2026-19516 is a critical SSRF issue in mcp-grafana where caller-controlled request headers and parameters allow an attacker to redirect outbound requests to arbitrary internal destinations and read responses. The NVD notes that the prior fix for CVE-2026-15583 limited token leakage but did not restrict the outbound destinations themselves.
## Technical Details
- The attacker can supply an X-Grafana-URL request header that controls the destination of mcp-grafana outbound requests.
- The grafana_api_request tool allows the caller to choose:
- the HTTP method
- the request path
- the request body
- Because the destination is not restricted to the configured Grafana instance, outbound traffic can be directed to:
- internal network services
- loopback services
- link-local network services
- metadata endpoints
- The attacker can read the responses returned from these internal targets, enabling data exposure.
- CWE classification: CWE-918 (Server-Side Request Forgery).
## Affected
- mcp-grafana (component name referenced in the NVD description).
## Impact
- Server-Side Request Forgery (SSRF) with response content disclosure.
- Potential access to sensitive internal resources, including metadata endpoints.
- Security impact aligns with the provided CVSS vector: AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L.
## Mitigation
1. Restrict outbound destinations so requests cannot be redirected via X-Grafana-URL to non-configured Grafana instances.
2. Enforce allowlisting of permitted hosts/IPs and block loopback/link-local/internal ranges as appropriate for the deployment.
3. Validate and constrain grafana_api_request inputs (method/path/body) so they cannot be used to probe arbitrary internal services.
4. Review and ensure the CVE-2026-15583 mitigation (token handling) remains in place, but do not rely on it as a substitute for destination restriction.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L
CWE-918