CVE-2026-55494 Tugtainer: Unauthenticated access to Tugtainer Agent Docker management APIs when AGENT_SECRET is unset
Attackers can access Docker management APIs without authentication if the agent secret is unset, allowing unauthorized container control.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-55494?
CVE-2026-55494 is a critical authentication bypass vulnerability in Quenary tugtainer, published on 30 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-284
Which versions are affected by CVE-2026-55494?
How do I fix CVE-2026-55494?
No fix has been published for CVE-2026-55494 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-55494 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55494 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-wgw2-c96g-p7h7.