GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.9 before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2 that, under certain conditions, could have allowed an authenticated user with a fine-grained Personal Access Token scoped only to user-boundary import permissions to import projects into group namespaces beyond the token's intended scope, due to incorrect authorization of the import target namespace.
Upgrade to versions 19.2.8, 19.3.5, 19.4.2 or above.