If 'everyone' or 'all members' can invite guests, any compromised user can create an attacker-controlled guest account, then use it as a persistence mechanism even after the original account's password is reset.
A scan reports where your tenant stands on this check — pass, fail with a step-by-step fix, or not applicable if your licensing doesn’t include the feature. When Tenant Strike can’t read a setting with read-only access, it says unverified and gives you a one-command way to confirm it yourself — it never guesses.
Check your own tenant
Is your tenant covered on "restrict guest invitations"?
One read-only scan answers it — this check and every other one in the catalog, each with a plain-English fix. 7-day Pro trial, no credit card.