Ghost before 5.42.1 allows remote attackers to read arbitrary files within the active theme’s folder via /assets/built%2F..%2F..%2F/ directory traversal. This occurs in frontend/web/middleware/static-theme.js.
View the template here CVE-2023-32235.yaml
References:
https://github.com/advisories/GHSA-wf7x-fh6w-34r6