A VPN certificate is a digital credential used to prove identity during VPN authentication. It is typically issued by a trusted certificate authority and contains a public key plus identifying information that a gateway can verify before allowing a tunnel to form. Unlike a password, it is meant to provide machine- or user-level trust that is harder to forge.
In cyber security, VPN certificates matter because they sit on the trust boundary of remote access. If certificate validation is weak, an attacker may impersonate a user, device, or peer, or trigger flaws in the code that parses certificate data. That can lead to bypassed authentication, denial of service, or even remote code execution in gateway software. Defenders rely on strict certificate checks, revocation handling, and careful patching of VPN appliances to reduce this risk.