The HTTP Content-Security-Policy (CSP) child-src directive defines the valid sources for web workers and nested browsing contexts loaded using elements such as <frame> and <iframe>. For workers, non-compliant requests are treated as fatal network errors by the user agent.
| CSP version | 2 |
|---|---|
| Directive type | Fetch directive |
default-src fallback | Yes. If this directive is absent, the user agent will look for the default-src directive. |
One or more sources can be allowed for the child-src policy:
Content-Security-Policy: child-src <source>; Content-Security-Policy: child-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: child-src https://example.com/
This <iframe> and worker are blocked and won't load:
<iframe src="https://not-example.com"></iframe> <script> const blockedWorker = new Worker("data:application/javascript,…"); </script>
| Specification |
|---|
| Content Security Policy Level 3 # directive-child-src |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
child-src |
40 |
15 |
45 |
No |
27 |
10 |
Yes |
Yes |
45 |
No |
9.3 |
Yes |
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https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/child-src