GHSA-x5mm-wm4g-j5xv: Ghost: Server-Side Request Forgery Mitigation Issue

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. 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. 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 security@ghost.org.