CVE-2026-55494

Tugtainer is a self-hosted app for automating updates of Docker containers. Prior to version 1.30.4, Tugtainer Agent allows unauthenticated access to Docker management APIs when AGENT_SECRET is not configured. The Agent uses request signatures to protect its API routes. However, in agent/auth.py, the signature verification function returns successfully if Config.AGENT_SECRET is empty. This causes protected Agent APIs to become accessible without authentication. This issue has been patched in version 1.30.4.

  • Published Sep 30, 2026
  • CVSS 9.8 critical
  • 0.6% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-55494 at the National Vulnerability Database