Content-Security-Policy: worker-src directive

The HTTP Content-Security-Policy (CSP) worker-src directive specifies valid sources for Worker, SharedWorker, or ServiceWorker scripts.

CSP version3
Directive typeFetch directive
Fallback

If this directive is absent, the user agent will first look for the child-src directive, then the script-src directive, then finally for the default-src directive, when governing worker execution.

Syntax

http
Content-Security-Policy: worker-src 'none';
Content-Security-Policy: worker-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.

<source-expression-list>

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:

Examples

undefined

Violation cases

Given this CSP header:

http
Content-Security-Policy: worker-src https://example.com/

Worker, SharedWorker, ServiceWorker are blocked and won't load:

html
<script>
  let blockedWorker = new Worker("data:text/javascript,…");
  blockedWorker = new SharedWorker("https://not-example.com/");
  navigator.serviceWorker.register("https://not-example.com/sw.js");
</script>

Specifications

See also