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.
Canada's Cyber Centre warned that Grafana Alloy versions through 1.18.1 are affected by CVE-2026-19516 and urged users to apply available updates.
Canada's Cyber Centre issued advisory AV26-860 warning that Grafana Alloy versions prior to or equal to 1.18.1 are affected by CVE-2026-19516. The bulletin directs users and administrators to vendor resources and available patches. No exploitation or severity details are included in the advisory text.