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We are aware of the recently disclosed PHP2Shell vulnerabilities (CVE-2026-109618 and CVE-2026-109619) and can confirm Filestack is not impacted by these vulnerabilities.

What Is a Custom CNAME?

Custom CNAME is a premium Filestack feature that serves Filestack URLs from your own domain.

Your Domain in File URLs

File URLs change from https://cdn.filestackcontent.com to a domain you choose, such as https://cdn.YOUR-DOMAIN.com. The custom domain also works for API requests. In the JavaScript SDK, set the cname option: filestack.init('apikey', { cname: 'fs.mydomain.com' }).

Security Policies in Cookies

With a custom CNAME, your website can set the security policy in a cookie in place of the URL. When a file URL is opened, Filestack checks the cookie before serving the file. Shared URLs do not contain the policy.

Setup

  • Filestack adds your domain to its managed wildcard SSL certificate
  • You add DNS records for each Filestack service you use
  • Cloud sources in the File Picker must use your own OAuth clients
  • Contact the Filestack sales team to set it up

Documentation

Read the Filestack documentation page for this term.

Open the documentation