An open redirect on the login form (and possibly other places) in Plone 4.0 through 5.2.1 allows an attacker to craft a link to a Plone Site that, when followed, and possibly after login, will redirect to an attacker's site.
"https://github.com/pypa/advisory-database/blob/main/vulns/plone/PYSEC-2020-85.yaml"