Ghost through 5.85.1 allows remote attackers to bypass an authentication rate-limit protection mechanism by using many X-Forwarded-For headers with different values. NOTE: the vendor's position is that Ghost should be installed with a reverse proxy that allows only trusted X-Forwarded-For headers.
https://github.com/TryGhost/Ghost/releases
https://ghost.org/docs/faq/proxying-https-infinite-loops/
https://docs.google.com/document/d/1iy0X4Vc9xXYoBxFrcW6ATo8GKPV6ivuLVzn6GgEpwqE