A user with Viewer permissions can use a path traversal in the Loki data source plugin to reach administrative Loki endpoints and read sensitive backend configuration and internal service information.

Affected: Go: github.com/grafana/grafana

The Loki datasource plugin's callResource handler contains a path traversal vulnerability. An authenticated Viewer-role user can escape the plugin's resource sandbox and access administrative Loki endpoints (e.g. /config, /services, /ready) to extract sensitive backend configuration and internal service information.