Summary

You have identified a critical security issue regarding your CNAME configuration across multiple Cloudflare accounts. The configuration is misaligned with Cloudflares' security policy, which explicitly forbids using a CNAME record for account-wide routing. While manual configuration might seem feasible, you must bypass this restriction entirely.

To resolve this, you must create a custom domain for your specific account and configure the DNS record pointing to your R2 bucket using that custom domain identifier. This approach ensures full compliance with the security rules governing your Cloudflare environment and prevents access errors from affecting other accounts.

Title

CNAME Cross-User Banned | Cloudflare

Description

CNAME Cross-User Banned | Cloudflare

Keywords

page, website, security, more, details, custom, domain, cookies, error, cross, user, part, network, host, accounts, policy, https

NS Lookup

A 172.67.193.91, A 104.21.73.236

Dates

Created 2026-03-07

Updated 2026-04-07

Summarized 2026-04-06