It is the application Docker that is not secure. Containers are. In fact Docker runs a daemon as root to wich you communicate from a client. This is what makes it less secure; running under root power. It also has a few shortcomings of privileged containers. This can be easily solved by using podman and SELinux. If you can manage to run Docker rootless, then you are magnitudes higher in security.
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
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