Zitat von MITs Forum am 2. Juni 2023, 0:00 Uhr

A duplicate SystemPrincipal object could be created when parsing a non-system html document via DOMParser::ParseFromSafeString. This could have lead to bypassing web security checks. This vulnerability affects Firefox < 109.

References
https://bugzilla.mozilla.org/show_bug.cgi?id=1802346
https://www.mozilla.org/security/advisories/mfsa2023-01/