Outlook 365 / 2021 / 2019 / 2016 Update for November 2023

The November security and rollup update has been made available for all Click-to-Run installations of Outlook 2016, Outlook 2019, Outlook 2021 and Outlook as part of a Microsoft 365 subscription.

It contains 4 security updates for Excel (2) and Office (2).

In addition, it contains 4 non-security fixes related to Outlook Current Channel Version 2310, 1 new feature and 5 fixes related to Outlook Monthly Enterprise Version 2309, 4 fixes related to Outlook Monthly Enterprise Version 2308, 4 fixes related to Outlook Semi-Annual (Preview) Version 2308, 1 fix related to Outlook Semi-Annual Version 2302, and 1 fix related to Outlook Semi-Annual Version 2208.

  • Version 2310
    • We fixed an issue that caused Outlook to fail to comply with the default browser settings for some users.
    • We fixed an issue that caused the labels from protected PDF files to not be applied to the email that they were attached to.
    • We fixed an issue where new lines were added to an Outlook signature when pressing Enter in the body of the email.
    • We fixed an issue that caused Outlook to exit unexpectedly when clicking the “More” link in the Search results list.
  • Version 2309
    • Updated encryption for Microsoft Purview Information Protection
      Advanced Encryption Standard (AES) with 256-bit key length in Cipher Block Chaining mode (AES256-CBC) is now the default Microsoft Purview Information Protection encryption mechanism for Microsoft 365 Apps documents and emails.
    • We fixed an issue that caused a meeting update to be sent to all attendees when clicking on “cancel” in the “Send Update to Attendees” dialog.
    • We fixed an issue that caused Outlook to exit unexpectedly after clicking “Cancel” on the Wait on Send dialog.
    • We fixed an issue that caused Outlook to exit unexpectedly when searching a shared or delegated mailbox.
    • We fixed an issue where the setting to control how Outlook opens previous items at start-up was missing from the Options window.
    • We fixed an issue where Microsoft account users were missing their Outlook Add-ins.
  • Version 2308
    • We fixed an issue that caused a meeting update to be sent to all attendees when clicking on “cancel” in the “Send Update to Attendees” dialog.
    • We fixed an issue that caused sensitivity labels to display incorrectly when they contain non-ASCII characters.
    • We fixed an issue that caused Outlook to exit unexpectedly after clicking “Cancel” on the Wait on Send dialog when attachments are present.
    • We fixed an issue that caused the labels from protected PDF files to fail to be applied to the email that they were attached to.
  • Version 2302
    • We fixed an issue that caused Outlook to exit unexpectedly after clicking “Cancel” on the Wait on Send dialog when attachments are present.
  • Version 2208
    • We fixed an issue that caused the body of meeting requests to sometimes be truncated or blank after applying the August 2023 security update.

Based on your release channel, you’ll be updated to the following version;

  • Microsoft 365 Apps, Outlook 2016 Retail, Outlook 2019 Retail, Outlook 2021 Retail
    Version 2310 (Build 16924.20150)
  • Monthly Enterprise
    Version 2309 (Build 16827.20278)
    Version 2308 (Build 16731.20398)
  • Semi-Annual Enterprise (Preview)
    Version 2308 (Build 16731.20398)
  • Semi-Annual Enterprise
    Version 2302 (Build 16130.20846)
    Version 2208 (Build 15601.20816) 
  • Outlook LTSC 2021
    Version 2108 (Build 14332.20604)
  • Outlook 2019 Volume Licensed
    Version 1808 (Build 10404.20013)

Note: Depending on your installation type, this update can be installed via the Update Now button in Outlook itself or the Microsoft Store. This update does not apply to msi-based installations of Office 2016.