CSP: frame-src
The HTTP Content-Security-Policy
(CSP)
frame-src
directive specifies valid sources for nested
browsing contexts loading using elements such as <frame>
and
<iframe>
.
Note: frame-src
allows you to specify where iframes in a page may be loaded from.
This differs from frame-ancestors
, which allows you to specify what parent source may embed a page.
CSP version | 1 |
---|---|
Directive type | Fetch directive |
Fallback |
If this directive is absent, the user agent will look for the
child-src directive (which falls back to the
default-src directive).
|
Syntax
One or more sources can be allowed for the frame-src
policy:
http
Content-Security-Policy: frame-src <source>;
Content-Security-Policy: frame-src <source> <source>;
Sources
<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).
Examples
Violation cases
Given this CSP header:
http
Content-Security-Policy: frame-src https://example.com/
The following <iframe>
is blocked and won't load:
html
<iframe src="https://not-example.com/"></iframe>
Specifications
Specification |
---|
Content Security Policy Level 3 # directive-frame-src |
Browser compatibility
BCD tables only load in the browser