An input validation issue allowed any staff user to create a post with content that could be used to hijack another staff user's Ghost Admin session resulting in privilege escalation.

This vulnerability is present in Ghost from v4.9.0 up 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 Versa for disclosing this vulnerability responsibly.

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