Using nginx in front of my local confluence server (not listening on the internet) and used the following:

  location ~\* \$\{. {
          deny all;
  }

but this only helps if this vulnerability is triggered using the request uri otherwise it's useless

The security advisory from Atlassian says blocking ${ "may reduce your risk". That's a far cry from being a fix.

posting a snippet for HAProxy in case its helpful to someone else (or if others have recommendations on how to better do this)

  http-request deny if { path -m sub ${ }
  http-request deny if { query -m sub ${ }
  http-request deny if { path -m sub $%7B }
  http-request deny if { query -m sub $%7B }
  http-request deny if { path -m sub %24%7B }
  http-request deny if { query -m sub %24%7B }