What did you do?

Calling the api Series with only an empty matcher increases by A LOT the memory (and cpu) usage.
One of my user basically OOM Killed my prometheus with a label_values on grafana on a label which does not exist.

curl -g 'http://<prometheus>/api/v1/series?match[]={foo=%22%22}'

What did you expect to see?

I would like prometheus to reject the matcher like it is with the query UI with the following query:

{foo=""}

• Prometheus version:
  v2.23.0 (happen on most releases)

Something else to add

Weirdly this API call answer instantly an empty success:

curl -g 'http://<prometheus>/api/v1/series?match[]={}'