PLEASE STOP REPORTING THIS ISSUE
Cloudflare caches images, even if the image is gone.
This means if you open an image and it's an error page, and Cloudflare caches the error page, it caches the error as YOU viewing it.
If someone else opens that same image, they get the same error. This means they see the error page as the PREVIOUS USER.
This is NOT a vulnerability. There is NO private information leaked when this happened. It is NOT A PROBLEM.
Cloudflare cannot be instructed to not cache error pages.