An access control issue in Argo CD v2.4.12 and below allows unauthenticated attackers to enumerate existing applications.
https://github.com/chunklhit/cve/blob/master/argo/argo-cd/application_enumeration.md
https://github.com/argoproj/argo-cd/security/advisories/GHSA-2q5c-qw9c-fmvq