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Unconfirmed Tailscale SSH flaws could spread root from one device

2 sources · 2 articlesFirst reported Updated ()1
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First merged summary.

Merged summary · x-ai/grok-4.7 · rewritten as coverage arrivesSummaries by Vani AI

Lab findings in Tailscale 1.104.2 and headscale 0.29.5 remain unconfirmed, with no CVE, bulletin, or fix.

Erica Windisch of Cyberdione Labs published the Tailworm report on October 25, 2026, describing 11 unconfirmed issues in Tailscale SSH, serve and app connectors, the DERP client, and headscale. Lab tests of Tailscale 1.104.2 and headscale 0.29.5, run October 22–24, found that with SSH port forwarding allowed and a foothold on one permitted device, an ordinary session could reach root on other servers and read /etc/shadow. Where Tailnet Lock was off, an attacker machine could be enrolled. Tailscale has not confirmed the specific claims and has published no CVE, bulletin, or fixed version. Vice president Mike Shaver said the company is fixing related issues and is not telling everyone to disable Tailscale SSH. The proof of concept is not public.

Key facts
  • Eleven findings cover Tailscale SSH, serve, app connectors, DERP, and headscale.
  • Tests used Tailscale 1.104.2 and headscale 0.29.5 from October 22 to 24.
  • Per-pair access rules stopped the spread in the lab tests.
  • On headscale 0.29.5, SSH forwarding cannot be turned off at all.
  • Enrollment-key abuse completed only when Tailnet Lock was not enabled.
  • A researcher says a headscale issue can exhaust memory without an account.
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Timeline

dated events in the reporting · oldest first
  1. Oct 22, 2026Lab tests of Tailscale and headscale began. · Cyber Security News
  2. Oct 24, 2026Three-day lab testing window ended. · Cyber Security News
  3. Oct 25, 2026Cyberdione Labs published the Tailworm report. · The Hacker News

What each outlet adds

beyond the shared facts
  • Cyber Security NewsSocket abuse, /etc/shadow read, sub-second hop, and memory exhaustion.
  • The Hacker NewsShaver response, Tailnet Lock condition, and nonpublic PoC.
Vendors
Tailscale
Products
Tailscale SSHheadscaletailscaled
Organizations
Cyberdione Labs

Coverage

oldest first · one row per article · UTC
  1. · 8h ago Cyber Security NewsFirst report

    Researcher reports Tailscale SSH flaws that can yield root across servers

    Eleven unconfirmed findings in tailscale 1.104.2 and headscale 0.29.5 have no CVE, bulletin, or fix.

  2. · 5h ago The Hacker News

    Unpatched Tailscale SSH flaws can yield root from one compromised device

    Lab tests on Tailscale 1.104.2 and headscale 0.29.5 found no CVE, bulletin, or fix as of October 25.