Researchers at the RWTH Aachen University in Germany published a study revealing that tens of thousands of container images hosted on Docker Hub contain confidential secrets, exposing software, online platforms, and users to a massive attack surface.
The most popular images on Docker Hub are official / library images, they are curated and monitored by Docker for best practices and security vulnerabilities. I’m not saying that means you should trust them completely, it’s always best practice to read the source of an image before you use it.