MediaWiki through 1.33.1 allows attackers to bypass the Title_blacklist protection mechanism by starting with an arbitrary title, establishing a non-resolvable redirect for the associated page, and using redirect=1 in the action API when editing that page.
https://www.debian.org/security/2019/dsa-4592
https://seclists.org/bugtraq/2019/Dec/48
https://phabricator.wikimedia.org/T239466
https://gerrit.wikimedia.org/r/q/Ie54f366986056c876eade0fcad6c41f70b8b8de8