All of the directives that end with -src support similar values known as a source list. Multiple source list values can be space separated with the exception of 'none' which should be the only value.

Source Value Example Description
* img-src * Wildcard, allows any URL except data: blob: filesystem: schemes
'none' object-src 'none' Prevents loading resources from any source
'self' script-src 'self' Allows loading resources from the same origin (same scheme, host and port)
data: img-src 'self' data: Allows loading resources via the data scheme (e.g. Base64 encoded images)
domain.example.com img-src domain.example.com Allows loading resources from the specified domain name
*.example.com img-src *.example.com Allows loading resources from any subdomain under example.com
https://cdn.com img-src https://cdn.com Allows loading resources only over HTTPS matching the given domain
https: img-src https: Allows loading resources only over HTTPS on any domain
'unsafe-inline' script-src 'unsafe-inline' Allows use of inline source elements such as style attribute, onclick, or script tag bodies (depends on the context of the source it is applied to)
'unsafe-eval' script-src 'unsafe-eval' Allows unsafe dynamic code evaluation such as Javascript eval()