Cal.com OSS ships lacks authorization on webhook teamId creation, allowing any authenticated user to create a webhook on any team via unvalidated teamId injection, then steal booking data, including fields like organizer/attendee emails and custom responses, and conditionally video-call passwords, by triggering webhook delivery.
https://vokecyber.com/research/calcom-cross-tenant-webhook-plant
https://github.com/calcom/cal.diy/security/advisories/GHSA-4fwh-xxpv-xfm6