Public dashboards with annotations enabled did not limit their annotation timerange to the locked timerange of the public dashboard. This means one could read the entire history of annotations visible on the specific dashboard, even those outside the locked timerange.
This did not leak any annotations that would not otherwise be visible on the public dashboard.
Every uncached /avatar/:hash request spawns a goroutine that refreshes the Gravatar image. If the refresh sits in the 10-slot worker queue longer than three seconds, the handler times out and stops listening for the result, so that goroutine blocks forever trying to send on an unbuffered channel. Sustained traffic with random hashes keeps tripping this timeout, so goroutine count grows linearly, eventually exhausting memory and causing Grafana to crash on some systems.