Sandboxing flags can be set, for example, with the sandbox attribute of certain elements or the sandbox CSP directive, and can be inherited across window open (depending on the value of sandboxing flags).
For now, Chromium is moving to disallow portal context creation in a sandboxed document (https://crbug.com/1051639).
There are a few other options here we could explore, like allowing it but inheriting sandbox flags, allowing it without inheriting flags, or either of those behaviors but requiring the presence of a similar allow-portals or allow-portals-to-escape-sandbox sandboxing flag.
Sandboxing flags can be set, for example, with the
sandboxattribute of certain elements or thesandboxCSP directive, and can be inherited across window open (depending on the value of sandboxing flags).For now, Chromium is moving to disallow portal context creation in a sandboxed document (https://crbug.com/1051639).
There are a few other options here we could explore, like allowing it but inheriting sandbox flags, allowing it without inheriting flags, or either of those behaviors but requiring the presence of a similar
allow-portalsorallow-portals-to-escape-sandboxsandboxing flag.