Content-Security-Policy: connect-src directive - HTTP | MDN (original) (raw)

Syntax

Content-Security-Policy: connect-src 'none';
Content-Security-Policy: connect-src <source-expression-list>;

This directive may have one of the following values:

'none'

No resources of this type may be loaded. The single quotes are mandatory.

A space-separated list of source expression values. Resources of this type may be loaded if they match any of the given source expressions. For this directive, the following source expression values are applicable:

• 'self'

Examples

Violation cases

Given this CSP header:

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

The following connections are blocked and won't load:

<a ping="https://not-example.com" href="/">Link</a>
<script>
  const response = fetch("https://not-example.com/");

  const xhr = new XMLHttpRequest();
  xhr.open("GET", "https://not-example.com/");
  xhr.send();

  const ws = new WebSocket("wss://not-example.com/");

  const es = new EventSource("https://not-example.com/");

  navigator.sendBeacon("https://not-example.com/", {
    /* … */
  });
</script>

Specifications

Browser compatibility

See also

• Content-Security-Policy
• ping
• fetch()
• XMLHttpRequest
• WebSocket
• EventSource