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AWS systems-manager-automation-runbooks documentation change

Service: systems-manager-automation-runbooks · 2026-04-16 · Documentation medium

File: systems-manager-automation-runbooks/latest/userguide/automation-aws-patchasginstance.md

Summary

Added a markdown link and an important note clarifying that the AutoPatchInstanceInASG tag is not a patch compliance indicator and providing guidance on how to verify patch compliance

Security assessment

This change adds documentation about security best practices for verifying patch compliance. It clarifies that a tag used by the runbook is not a compliance indicator and directs users to proper methods (DescribeInstancePatchStates, ListComplianceItems) for verification. This helps prevent misconfiguration and ensures accurate security posture assessment, but does not address a specific security vulnerability.

Diff

diff --git a/systems-manager-automation-runbooks/latest/userguide/automation-aws-patchasginstance.md b/systems-manager-automation-runbooks/latest/userguide/automation-aws-patchasginstance.md
index 22bb2e286..235ee6035 100644
--- a//systems-manager-automation-runbooks/latest/userguide/automation-aws-patchasginstance.md
+++ b//systems-manager-automation-runbooks/latest/userguide/automation-aws-patchasginstance.md
@@ -0,0 +1,2 @@
+[View a markdown version of this page](automation-aws-patchasginstance.md)
+
@@ -12,0 +15,6 @@ Patch Amazon Elastic Compute Cloud (Amazon EC2) instances in an Auto Scaling gro
+###### Important
+
+This runbook applies an `AutoPatchInstanceInASG` tag to the target instance during execution. This tag prevents the runbook from executing twice on the same instance simultaneously — it is not a patch compliance indicator. If the patching step fails, the tag value might still be set to `Completed` even though the runbook execution status reports `Failed`.
+
+To verify patch compliance on the instance, use [DescribeInstancePatchStates](https://docs.aws.amazon.com/systems-manager/latest/APIReference/API_DescribeInstancePatchStates.html) or [ListComplianceItems](https://docs.aws.amazon.com/systems-manager/latest/APIReference/API_ListComplianceItems.html) instead.
+