Ensure that SharePoint guest users cannot share items they don't own
Why This Matter
Guest users who can share items they do not own introduce a significant data leakage risk in SharePoint Online. When external collaborators gain the ability to reshare content, you lose control over who ultimately accesses sensitive information. This setting prevents unauthorized disclosure by ensuring only item owners decide who can view or edit their content.
What Aether365 Checks
Aether365 verifies that the SharePoint Online tenant setting PreventExternalUsersFromResharing is set to True. This check appears in your Aether365 dashboard under the Microsoft 365 security checks section.
How to Fix
Using the Microsoft 365 Admin Center: