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AWS controltower: Clarify OU re-registration during landing zone upgrade

Service: controltower · 2026-09-27 · Documentation low

File: controltower/latest/userguide/lz-version-selection.md

Summary

Reworded step 5 to state that registered OUs must be re-registered to apply the updated baseline to all accounts in the OU.

Security assessment

Procedural clarification about applying baselines via OU re-registration; no specific vulnerability or security feature is documented.

Evidence

+  5. After the landing zone is updated, you might need to update your registered OUs. To update an OU, you must re-register it by using the **Re-register OU** process. Re-registering an OU applies the updated baseline to all accounts in that OU.

Diff

diff --git a/controltower/latest/userguide/lz-version-selection.md b/controltower/latest/userguide/lz-version-selection.md
index 9cafa202d..937ba778a 100644
--- a//controltower/latest/userguide/lz-version-selection.md
+++ b//controltower/latest/userguide/lz-version-selection.md
@@ -31 +31 @@ In conversation, moving to a newer version is often referred to as an _upgrade_
-  5. After the landing zone is updated, you may need to update your accounts. The easiest way to do the account updates is by a **Re-register OU** process for each of your registered OUs.
+  5. After the landing zone is updated, you might need to update your registered OUs. To update an OU, you must re-register it by using the **Re-register OU** process. Re-registering an OU applies the updated baseline to all accounts in that OU.