CSP navigation directives are used in a Content-Security-Policy header and govern to which location a user can navigate to or submit a form to, for example.
Navigation directives don't fall back to the default-src directive.
List of CSP Navigation directives
form-action- Restricts the URLs which can be used as the target of a form submissions from a given context.
frame-ancestors- Specifies valid parents that may embed a page using
<frame>,<iframe>,<object>,<embed>, or<applet>. navigate-to- Restricts the URLs to which a document can initiate navigation by any means, including
<form>(ifform-actionis not specified),<a>,window.location,window.open, etc.