One or more sources can be allowed for the img-src policy:

Content-Security-Policy: img-src <source>;
Content-Security-Policy: img-src <source> <source>;

<source> can be any one of the values listed in CSP Source Values.

Note that this same set of values can be used in all fetch directives (and a number of other directives).

Given this CSP header:

Content-Security-Policy: img-src https://example.com/

The following <img> is blocked and won't load:

<img src="https://not-example.com/foo.jpg" alt="example picture" />

• Content-Security-Policy
• <img>