Yes, considerations for CORS headers are necessary in this scenario.

When using a Cloudflare Worker to supply a key for accessing a PDF asset from a Backblaze private repository, the following should be considered:

1 Cloudflare Worker Response: Ensure that the Cloudflare Worker includes appropriate CORS headers in its response to the client. This typically involves setting the Access-Control-Allow-Origin header to allow the requesting origin.
2 Backblaze Response: If the PDF is fetched directly from Backblaze by the client, Backblaze must also include the necessary CORS headers in its response. If the Cloudflare Worker fetches the PDF and then serves it to the client, the Worker should handle CORS.
3 Security: Ensure that the CORS policy is configured to allow only trusted origins to access the resource, minimizing security risks.

By properly configuring CORS headers, you can ensure that the PDF is accessible while maintaining security.