Microsoft to Block Unauthorized Scripts in Entra ID Logins with 2026 CSP Update

Microsoft has announced plans to improve the security of Entra ID authentication by blocking unauthorized script injection attacks starting a year from now.
The update to its Content Security Policy (CSP) aims to enhance the Entra ID sign-in experience at “login.microsoftonline[.]com” by only letting scripts from trusted Microsoft domains run.
“This update strengthens security and adds an extra