WordPress before 5.5.2 mishandles embeds from disabled sites on a multisite network, as demonstrated by allowing a spam embed.
lists.debian.org/debian-lts-announce/2020/11/msg00004.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CHHVNK2WYAM3ZTCXTFSEIT56IKLVJHU3/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VAVVYJKA2I6CRQUINECDPBGWMQDEG244/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUXVUAKL2HL4QYJEPHBNVQQWRMFMII2Y/
wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release/
www.debian.org/security/2020/dsa-4784