Craft is a flexible, user-friendly CMS for creating custom digital experiences on the web and beyond. This is an remote code execution (RCE) vulnerability that affects Craft 4 and 5 installs where your security key has already been compromised. Anyone running an unpatched version of Craft with a compromised security key is affected. This vulnerability has been patched in Craft 5.5.8 and 4.13.8. Users who cannot update to a patched version, should rotate their security keys and ensure their privacy to help migitgate the issue.