VDP stands for Vulnerability Disclosure Policy. It is a formal process that tells security researchers how to report a flaw, what systems are in scope, what information to include, and how the recipient will handle the report. A good VDP usually names a contact path, sets expectations for response, and explains whether safe-harbor terms apply.
VDPs matter because they turn ad hoc bug reports into a managed security workflow. In practice, they help defenders triage issues faster, reduce confusion, and route findings to the right product or incident-response team. In real attacks, the same weaknesses that are reported under a VDP may later be exploited if they are ignored, so the policy is a defense mechanism as much as a communications tool. It also gives researchers a clear channel instead of forcing public disclosure to get attention.