phpMyFAQ from 4.2.0-alpha.2 before 4.2.0-beta contains a privilege escalation vulnerability in the group permission API, whose updatePermissions and updateMembers endpoints check held rights without regard to language or category scope and write unrestricted group grants. Non-superadmin administrators holding GROUP_EDIT can grant a group a right they hold only in a narrow scope and self-join it via updateMembers, gaining unrestricted FAQ create, edit, and publish access across all languages and categories.