Just a quick notice for anyone using this software in their homelab. Tailscale has released v1.104.4 to address a series of prominent vulnerabilities disclosed last week. These vulns affect the Tailscale Serve and Tailscale SSH functionalities of the software, and allow already-authorized attackers to gain further privileges erroneously. Kindly update to that version or higher, especially if you are using one of the SSH/Serve features.
For headscale selfhosters that also use Tailscale SSH, consider setting TS_SSH_DISABLE_FORWARDING=1 on all clients, as headscale does not have a way to force turning off SSH forwarding (one of the attack vectors). Headscale also has a relevant disclosed vulnerability affecting node registration, and an in-progress patch for that which is trackable here.
Finally, do give your SSH grants/access control list a review again. You may also disable these ssh/serve features if you don’t need them (and even compile the binary without them if you know how), and consider traditional alternatives such as OpenSSH + normal reverse proxy.
Further links:
- Tailscale’s blogpost on findings and fixes, with security recommendations
- Tailscale’s security bulletin for more info on the vulnerabilities (see TS-2026-014 to TS-2026-017)
- Their prior investigation notes here
Thanks for flagging this. Tailscale SSH is how I get into my Ubuntu Server boxes, so this one applies to me. The machines page in the admin console lists the client version for every node, which is the quickest way to spot the one box that didn’t take the update. Hosts that pull from Tailscale’s apt repo get it with normal updates, but anything installed another way, like a container image or a hand-installed binary on a cloud VM, can sit on an old version for a long time.
Just to clarify, this is only exploitable for people which already has access to your tailnet. So people you already gave access. External attackers can’t do anything. But keep your software updated as always.
This feels like it has validated my decision to just use plain wireguard and hardcode my client list. It’s really not too hard to set up, barely different that configuring authorized_keys or ssh.
That’s one of my TODOs on NixOS but I keep procrastinating on that. Today I finally set up adguard home locally on my PC and I want to make it available as a VPN(?) on my phone so I may finally get around to doing that soon-ish. I have zero clue how any of that works or how to set it up, however. Lol
This seems like a decent guide on how to set it up:
https://www.cyberciti.biz/faq/how-to-set-up-wireguard-firewall-rules-in-linux/
It’s very similar to the config I’ve got. The nat iptables stuff in step 1 is what enables wireguard to be used as a VPN exit node. (+ net.ipv4.ip_forward=1)
The only downside is that it’s not redundant. I wish it was, somehow.
