Some users may experience issues logging into Outlook.com

Title: Some users may be unable to sign in to Outlook.com through Chromium based browsers
User impact: Users may be unable to sign in to Outlook.com through Chromium based browsers.
More info: This issue only impacts users who sign in with a password. Those who sign in through Passkey or authentication prompts aren't impacted by this event. Affected users may be able to successfully sign in using a non-Chromium based browser, such as Firefox.
Current status: A recent configuration change to update the sign in flow is resulting in some password-based sign in requests being blocked. We’re reverting the affected configuration to a previous healthy version and monitoring the service as the change propagates across affected environments to ensure successful restoration.
Start time: Saturday, January 10, 2026, at 7:00 AM UTC
Next update by: Saturday, January 10, 2026, at 6:30 PM UTC

Title: Some users may experience issues logging into Outlook.com
User impact: Users may experience issues logging into Outlook.com.
Current status: We're continuing to review network and system logs, along with recent changes, to identify the root cause of the impact and inform an appropriate mitigation plan.
Next update by: Saturday, January 10, 2026, at 4:30 PM UTC

Title: Some users may experience issues logging into Outlook.com
User impact: Users may experience issues logging into Outlook.com.
Current status: We're conducting a detailed review of network and system logs to isolate the root cause and support development of an effective mitigation strategy.
Next update by: Saturday, January 10, 2026, at 2:30 PM UTC

Title: Some users may experience issues logging into Outlook.com
User impact: Users may experience issues logging into Outlook.com.
Current status: We're reviewing service monitoring telemetry to isolate the source of the issue and establish a fix.
Next update by: Saturday, January 10, 2026, at 12:30 PM UTC