Executive brief
Portainer CE is a popular container management platform used to simplify Docker and Kubernetes administration. An authentication bypass vulnerability allows low-privileged authenticated users to exploit URL normalization issues to gain root-level access to the underlying Docker host, bypassing all authorization controls and enabling complete infrastructure compromise.
Technical details
This is an authentication bypass vulnerability in the Docker proxy endpoint caused by insufficient URL normalization before applying authorization middleware. The proxy fails to canonicalize request paths, allowing crafted URLs to be interpreted differently by the authorization layer and the proxy handler. An authenticated user with low privileges can craft non-canonical URLs to bypass access control checks and gain root-level access to the Docker daemon. The vulnerability requires existing authentication credentials but allows privilege escalation from low to root. A patch is expected to normalize URLs before authorization checks are applied.
Affected products
- Portainer CE through 2.44.0
Timeline
- 2026-08-11: disclosed