The HTTP Content-Security-Policy (CSP) default-src directive serves as a fallback for the other CSP fetch directives. For each of the following directives that are absent, the user agent looks for the default-src directive and uses this value for it:
child-srcconnect-srcfont-srcframe-srcimg-srcmanifest-srcmedia-srcobject-srcprefetch-srcscript-srcscript-src-elemscript-src-attrstyle-srcstyle-src-elemstyle-src-attrworker-src| CSP version | 1 |
|---|---|
| Directive type | Fetch directive |
One or more sources can be allowed for the default-src policy:
Content-Security-Policy: default-src <source>;
Content-Security-Policy: default-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).
If there are other directives specified, default-src does not influence them. The following header:
Content-Security-Policy: default-src 'self'; script-src https://example.com
is the same as:
Content-Security-Policy: connect-src 'self';
font-src 'self';
frame-src 'self';
img-src 'self';
manifest-src 'self';
media-src 'self';
object-src 'self';
script-src https://example.com;
style-src 'self';
worker-src 'self'
| Specification |
|---|
| Content Security Policy Level 3 # directive-default-src |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
default-src |
25
|
14
|
23
|
No
|
15
|
7
|
Yes
|
Yes
|
23
|
Yes
|
7
|
Yes
|
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https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/default-src