Do SSH and VPNs support post-quantum key exchange?
Increasingly, yes, but you have to check each product. OpenSSH made a hybrid post-quantum key exchange its default in version 9.0 in 2022, and version 10.0 in 2025 made the ML-KEM-based hybrid mlkem768x25519-sha256 the default; if both ends run current releases, your SSH sessions probably already use it. For VPNs the picture varies. The IPsec key exchange IKEv2 gained a standard way to add extra key exchanges, such as ML-KEM, in RFC 9370, and some vendors and open-source projects support it while others have only announced it. WireGuard can add a pre-shared symmetric key as an extra post-quantum protection layer, but its handshake itself is classical. Check the release notes of your firewall or VPN gateway firmware and the client versions actually in use, and remember that an old server at one end keeps the whole connection classical. Remote-access and site-to-site VPNs carry a lot of long-lived data, so they deserve a high place in your migration order.