MC931401 - Ensuring Security and Compliance: Keep your Microsoft Teams desktop clients up to date

Updated December 18, 2024: We've delayed further rollouts of warning banners and blocking pages in December and intend to resume in mid-January per the schedule below. Please review for updated information and timing.

In today’s security climate, our work across the company and greater industry to keep this critical ecosystem secure is more important than ever. And while we also ship bug fixes and other new features via continuous innovation, in the end security is job one.

Keeping Microsoft Teams up to date is critical to ensure your devices are secure and compliant. By default, and as designed, Teams updates automatically which successfully updates most clients in the world without additional overhead for customers.

Microsoft Teams is governed by the Modern Lifecycle Policy which requires that the Teams desktop client be kept up to date. This is not a new policy, for instance in MC298823 (November 2021), a version that is far out of date will become incompatible with the service until it’s updated. As documented, when a client falls out of date, the user will see:

• Recurring in-app alerts, if the app is between 30d-90d out of date. Except in VDI environments, where this will occur between 60-90 days out of date.
• A blocking page in Teams, if the app is greater than 90 days out of date. At this point, the app will show options to update, to contact their IT administrator, or continue to Teams on the web.

As an example, if the Teams app is hypothetically on a version released on January 1 and the next update is fully available on January 15, an in-app alert would be shown on February 14th (30 days after the January 15th update).

For reference, link to the Teams app's version's release dates. Also, The Microsoft Teams desktop client usage report gives you an overview of the Teams desktop clients in use within your organization.

Classic Teams is not in scope for this post; see MC783985 for Classic Teams Timelines regarding end of support and end of availability.

When this will happen:

The existing policy enforcement will be visible beginning January 14th, 2025.

How this will affect your organization:

New Teams - Windows & Mac Versions desktop clients (not running in a VDI environment)

• Beginning January 14th, 2025, Teams desktop clients more than 30 days out of date, will present a banner or notification to users that they are on an outdated version of Teams. 
• Beginning February 18th, 2025, Teams desktop clients older than 90 days out of date, will present a blocking page. They will be shown an option to update to the latest version of Teams from this page or use Teams on the web. 

New Teams app running in a VDI environment – Windows desktop clients will follow the same policies as non-VDI environments, with enforcement starting on dates below 

• Beginning March 11th, 2025, for clients more than 60 days out of date will get a banner or notification to users that they are on an outdated version of Teams. 
• Beginning May 6th, 2025, for clients older than 90 days out of date, the Teams desktop client will present a blocking page. 

Note on Deployment of Changes: 

• Users in preview rings will experience the changes approximately 4 weeks before the specified dates (for app versions released to that ring). 
• The experiences above will not be visible to all users right away. It will take 4-8 weeks for the deployment to reach all users. 

What you can do to prepare:

To avoid disruption to end-users, the admins with users on Teams versions older than the currently released versions, should update their users to the most recent version.

Admins should make sure Teams is automatically updating to stay current and within the compatibility window. Common configurations to validate include:

• Teams clients on macOS have Microsoft AutoUpdate (MAU) configured properly. Learn More
• Customer network settings, and any device management software e.g. antivirus, are configured properly to allow automatic updates.
• Windows Policies must not block new Teams or the Webview2 updater.

Please visit this page to learn more.