GHSA-x5mm-wm4g-j5xv

### Impact A validation issue allowed some functionality, such as Webmentions, to be abused by an unauthenticated user to make limited HTTP requests to hosts in the Ghost server's internal network. A successful attack would not result in any response data being returned. ### Vulnerable versions This vulnerability is present in Ghost from v6.26.0 up to v6.54.0. ### Patches v6.54.1 contains a fix for this issue. ### How to update 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](https://docs.ghost.org/install/docker#updating-ghost). If your Ghost is a Ghost-CLI install see our documentation on [updating it to the latest version here](https://docs.ghost.org/update). ### References Ghost thanks Hwang Seyeon for disclosing this vulnerability responsibly. ### For more information If you have any questions or comments about this advisory, email Ghost at [[email protected]](mailto:[email protected]).