Skip to Content

MC343794: Office TLS Certificate Changes

Microsoft 365 is updating services powering messaging, meetings, telephony, voice, and video to use TLS certificates from a different set of Root Certificate Authorities (CAs) due to pending expiration of the Root CA.

MC343794: Office TLS Certificate Changes

Affected workloads

  • Skype for Business
  • Microsoft Teams
  • Microsoft Kaizala

Key points

  • Timing: June 30, 2022
  • Action: Update custom applications that rely on certificate pinning to mitigate interruption in service

How this affects your organization

The new Root CA “DigiCert Global Root G2” is widely trusted by operating systems including Windows, macOS, Android, and iOS and by browsers such as Microsoft Edge, Chrome, Safari, and Firefox.

Note: We expect that most Microsoft 365 customers will not be impacted.

However, if you have a custom application, your application may be impacted if it explicitly specifies a list of acceptable CAs. This practice is known as “certificate pinning”. Customers who do not have the new Root CAs in their list of acceptable CAs will receive certificate validation errors, which may impact the availability or function of your application.

Affected products include:

  • Microsoft Teams
  • Skype
  • Skype for Business Online
  • GroupMe
  • Kaizala
  • Azure Communication Services

Affected endpoints include (but are not limited to):

  • *.teams.microsoft.com
  • *.skype.com
  • *.skypeforbusiness.com
  • *.groupme.com
  • *.communication.azure.com
  • *.operatorconnect.microsoft.com

Additionally, Teams and Skype for Business Online endpoints in US Government national cloud instances of Microsoft 365 will make the same change, affecting endpoints such as:

  • *.gcc.teams.microsoft.com
  • *.dod.teams.microsoft.us
  • *.gov.teams.microsoft.us
  • *.online.dod.skypeforbusiness.us
  • *.online.gov.skypeforbusiness.us
  • *.um-dod.office365.us
  • *.um.office365.us

Services began transitioning to the new Root CAs beginning in January 2022 and will continue through October 2022.

What you can do to prepare

For more details on how to determine if you are affected by this change as well as the details of the new Root CAs, please refer to the technical guidance at Office TLS Certificate Changes.

Learn more

Message ID: MC343794
Published: 16 March 2022
Updated: 16 March 2022
Action required by: 30 June 2022
Major change: True
#AdminImpact #365Apps #Microsoft365 #Teams #Skype
Plan For Change

Alex Lim is a certified IT Technical Support Architect with over 15 years of experience in designing, implementing, and troubleshooting complex IT systems and networks. He has worked for leading IT companies, such as Microsoft, IBM, and Cisco, providing technical support and solutions to clients across various industries and sectors. Alex has a bachelor’s degree in computer science from the National University of Singapore and a master’s degree in information security from the Massachusetts Institute of Technology. He is also the author of several best-selling books on IT technical support, such as The IT Technical Support Handbook and Troubleshooting IT Systems and Networks. Alex lives in Bandar, Johore, Malaysia with his wife and two chilrdren. You can reach him at [email protected] or follow him on Website | Twitter | Facebook

    Ads Blocker Image Powered by Code Help Pro

    Your Support Matters...

    We run an independent site that is committed to delivering valuable content, but it comes with its challenges. Many of our readers use ad blockers, causing our advertising revenue to decline. Unlike some websites, we have not implemented paywalls to restrict access. Your support can make a significant difference. If you find this website useful and choose to support us, it would greatly secure our future. We appreciate your help. If you are currently using an ad blocker, please consider disabling it for our site. Thank you for your understanding and support.