Ghost Admin did not invalidate existing sessions on login which could have allowed for session fixation attacks. Successful exploitation would have required another vulnerability on the same domain where Ghost Admin was hosted.

This vulnerability is present in Ghost from v2.2.0 to v6.54.0.

v6.54.1 contains a fix for this issue.

For self-hosters using Docker, find [Docker's official Ghost image here](https://hub.docker.com/ /ghost). Updating a Docker-based Ghost instance is documented here.

If your Ghost is a Ghost-CLI install see our documentation on updating it to the latest version here.

Ghost thanks meifukun for disclosing this vulnerability responsibly.

If you have any questions or comments about this advisory, email Ghost at security@ghost.org.