Browser Extension Allowlist#

When attempting to implement browser extension lockdown1 (ie. only allowing authorized browser extensions to be installed), I came across some hidden extensions that needed to be allowed. Shortly after implementing a browser extension allowlist in Edge through Group Policy, users started calling and asking why the Teams/Outlook/Copilot sidebar 2 in Edge suddenly disappeared.

After some looking, I came across the following page edge://sidebar-internals where you can identify the built-in browser extension IDs for the Edge sidebar “extensions” for Outlook, Teams, Copilot, etc.

Adding the following extension IDs to the allowlist made the Edge sidebar reappear.

kfihiegbjaloebkmglnjnljoljgkkchm - Outlook

piilhopgoheagglmepbmkpodfceclmab - Teams

ofefcgjbeghpigppfmkologfjadafddi - Copilot

Screenshot showing Microsoft Edge sidebar with Outlook, Copilot, etc. app icons.

Screenshot showing example Windows Group policy with extension allowlist.

References#

  1. https://learn.microsoft.com/en-us/deployedge/microsoft-edge-browser-policies/extensioninstallallowlist  ↩︎

  2. https://learn.microsoft.com/en-us/deployedge/microsoft-edge-sidebar  ↩︎