XSS can occur in GNOME Web (aka Epiphany) before 40.4 and 41.x before 41.1 when View Source mode or Reader mode is used, as demonstrated by a a page title.
https://www.debian.org/security/2022/dsa-5042
https://lists.debian.org/debian-lts-announce/2022/08/msg00006.html
https://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/1045