Docker Container Security

The cluster discusses the security limitations of Docker containers, emphasizing they are not reliable sandboxes due to shared kernels and breakout risks, often recommending VMs, rootless modes, or tools like gVisor for better isolation.

➡️ Stable 0.8x Security
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Keywords

NewsBlur PodSecurityPolicy CE AppArmor PyCharm OS github.com VM ycombinator.com docker.com docker containers container security root docker containers vulnerability selinux isolation default

Sample Comments

eptcyka Feb 9, 2021 View on HN

Docker containers are not security boundaries, unless ran on top of firecracker or gVisor.

subsection1h Jan 13, 2026 View on HN

Containers aren't a sandbox:https://news.ycombinator.com/item?id=46405993

ryan-c Sep 17, 2014 View on HN

You should be assuming Docker is insecure until proven otherwise. Fully isolating a root user with a shared kernel is very difficult.

a022311 Oct 31, 2025 View on HN

Not sure how secure this really is, because it's fairly easy to break out of a Docker container with the default settings (due to the fact that the kernel is shared between containers and the host, unlike with VMs). Rootless Docker (or better, Podman) would improve security greatly.

airhead969 May 18, 2021 View on HN

Docker containers aren't provably secure. If you want isolation, use a VM that doesn't have host file system access. This way, if the VM is compromised, just throw it away and it can't leak out the way containers do.

pawadu Mar 8, 2016 View on HN

Please don't shrug this off so easily. With a vulnerability in the Docker daemon (an no software is 100% free of bugs) he is in more danger than before containerization.

0x0 Feb 21, 2015 View on HN

Are Docker containers actually sensibly secure as sandboxes? I thought there were still some gaps that needed to be closed in the underlying tech for it to be as safe as virtualization?

teacup50 Dec 3, 2014 View on HN

Relying on containers for security is a recipe for none.

LinuxBender Aug 10, 2015 View on HN

Docker is just a container and not a sandbox. There are no controls in the kernel to prevent something from leaving the container unless you enable restrictions outside of docker such as SELinux. There is a lot of development around SELinux+Docker right now.

Seattle3503 Jun 9, 2024 View on HN

How do people feel about using docker to prevent this sort of thing? Does it strike the right balance between usability and security?