Yep it has been implemented but it's still incomplete (see https://bugzilla.mozilla.org/show_bug.cgi?id=1978985#c22). About the CVE, I don't know.
Bug 1978985 Comment 24 Edit History
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Yep it has been implemented but it's still incomplete (see https://bugzilla.mozilla.org/show_bug.cgi?id=1978985#c22). About the CVE, I don't know, but maybe Dan knows.