Port 5900: VNC

Port 5900 is VNC, a cross-platform remote desktop protocol. Base VNC is unencrypted, so tunnel it over SSH or a VPN rather than exposing it directly.

TCPRemote accessUnencrypted by defaultIANA assigned
Port number5900
ServiceVirtual Network Computing
ProtocolTCP
CategoryRemote access
Default encryptionNo
Security note. Port 5900 is not encrypted by default. Restrict it to trusted networks, or use an encrypted alternative where one exists, to avoid exposing credentials and data in transit.

Frequently asked questions

What is port 5900 used for?

Port 5900 is VNC, a cross-platform remote desktop protocol. Base VNC is unencrypted, so tunnel it over SSH or a VPN rather than exposing it directly.

Is port 5900 TCP or UDP?

Port 5900 (VNC) uses TCP.

Is port 5900 secure?

Port 5900 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.

Should I open port 5900 on my firewall?

Only if you specifically need VNC. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.