Mastodon through 4.0.2 allows attackers to cause a denial of service (large Sidekiq pull queue) by creating bot accounts that follow attacker-controlled accounts on certain other servers associated with a wildcard DNS A record, such that there is uncontrolled recursion of attacker-generated messages.
{ "cpes": [ "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*" ], "severity": "High" }