Erica Windisch of Cyberdione Labs published a security assessment report called Tailworm on 25 October 2026, according to The Hacker News, covering Tailscale client v1.104.2 and headscale v0.29.5 (the self-hosted control server), which the report says were tested in a lab from 22 to 24 October.

The report says Tailscale SSH's Unix-socket forwarding performs path checks and file operations as root, so an ordinary session from one approved device can lead to root execution on target servers, capture of enrollment keys and arbitrary root-file deletion.

The report says the attacker needs a foothold on one device plus one SSH policy rule letting it connect, with forwarding granted automatically on headscale and set per rule on Tailscale's hosted service.

The report also lists findings in Tailscale's experimental conn25 app connectors, the headscale control server, the DERP relay client and tailscale serve.

According to The Hacker News, the findings rest on Windisch's report alone, no other researcher has publicly reproduced them, and Windisch wrote that the work was 'reported but not coordinated' with Tailscale.

The Hacker News also reports that Tailscale vice president of engineering Mike Shaver wrote on Reddit that Tailscale had received the report, had found issues it is working to fix, and is 'not recommending that everyone disable Tailscale SSH'.

Tailscale's security bulletins page listed no bulletin for these findings when checked on 26 October (Perth).