diff --git a/aws-rds-dbinstance/src/main/java/software/amazon/rds/dbinstance/BaseHandlerStd.java b/aws-rds-dbinstance/src/main/java/software/amazon/rds/dbinstance/BaseHandlerStd.java
index 6ea67dc87..dc3428a68 100644
--- a/aws-rds-dbinstance/src/main/java/software/amazon/rds/dbinstance/BaseHandlerStd.java
+++ b/aws-rds-dbinstance/src/main/java/software/amazon/rds/dbinstance/BaseHandlerStd.java
@@ -112,6 +112,7 @@
 import software.amazon.rds.dbinstance.status.OptionGroupStatus;
 import software.amazon.rds.dbinstance.status.ReadReplicaStatus;
 import software.amazon.rds.dbinstance.status.VPCSecurityGroupStatus;
+import software.amazon.rds.dbinstance.util.ResourceModelHelper;
 
 public abstract class BaseHandlerStd extends BaseHandler<CallbackContext> {
 
@@ -385,6 +386,9 @@ protected ApiVersionDispatcher<ResourceModel, CallbackContext> getApiVersionDisp
 
     protected void validateRequest(final ResourceHandlerRequest<ResourceModel> request) throws RequestValidationException {
         Validations.validateSourceRegion(request.getDesiredResourceState().getSourceRegion());
+        Validations.validateSourceRegion(request.getDesiredResourceState().getAutomaticBackupReplicationRegion());
+        assertValidRegionFromArnOrIdentifier(request.getDesiredResourceState().getSourceDBInstanceIdentifier());
+        assertValidRegionFromArnOrIdentifier(request.getDesiredResourceState().getSourceDBClusterIdentifier());
     }
 
     protected abstract ProgressEvent<ResourceModel, CallbackContext> handleRequest(
@@ -671,6 +675,19 @@ private void assertNoTerminalStatus(final DBInstance dbInstance) throws CfnNotSt
         assertNoDomainMembershipTerminalStatus(dbInstance);
     }
 
+    /**
+     * There are fields in the request (e.g. SourceDBInstanceIdentifier and SourceDBClusterIdentifier) that accept 2 types
+     * of identifiers: InstanceId or ARN. In the case of containing an ARN, we need to validate that the region is correct,
+     * as it will be used to contract the client endpoint, and a malformed region would lead to both security issues
+     * and also would return misleading error to the customer.
+     */
+    private static void assertValidRegionFromArnOrIdentifier(final String identifierOrArnField) throws RequestValidationException {
+        if (StringUtils.isNotBlank(identifierOrArnField) && ResourceModelHelper.isValidArn(identifierOrArnField)) {
+            final String sourceRegion = ResourceModelHelper.getRegionFromArn(identifierOrArnField);
+            Validations.validateSourceRegion(sourceRegion);
+        }
+    }
+
     protected boolean isDBInstanceStabilizedAfterMutate(
             final ProxyClient<RdsClient> rdsProxyClient,
             final ResourceModel model,
diff --git a/aws-rds-dbinstance/src/test/java/software/amazon/rds/dbinstance/CreateHandlerTest.java b/aws-rds-dbinstance/src/test/java/software/amazon/rds/dbinstance/CreateHandlerTest.java
index d0b2c1a6b..c529cf7b9 100644
--- a/aws-rds-dbinstance/src/test/java/software/amazon/rds/dbinstance/CreateHandlerTest.java
+++ b/aws-rds-dbinstance/src/test/java/software/amazon/rds/dbinstance/CreateHandlerTest.java
@@ -2258,4 +2258,84 @@ public void fetchEngineForUnknownScenario() {
                 expectFailed(HandlerErrorCode.InvalidRequest)
         );
     }
+
+    @Test
+    public void invalidSourceRegion() {
+        expectServiceInvocation = false;
+        final CallbackContext context = new CallbackContext();
+        context.setCreated(true);
+        context.setUpdated(true);
+        context.setRebooted(true);
+        context.setUpdatedRoles(true);
+        context.setAddTagsComplete(true);
+
+        test_handleRequest_base(
+                context,
+                null,
+                () -> RESOURCE_MODEL_BAREBONE_BLDR()
+                        .sourceRegion("clearlyNotAValidRegion")
+                        .build(),
+                expectFailed(HandlerErrorCode.InvalidRequest)
+        );
+    }
+
+    @Test
+    public void invalidAutomaticBackupReplicationRegion() {
+        expectServiceInvocation = false;
+        final CallbackContext context = new CallbackContext();
+        context.setCreated(true);
+        context.setUpdated(true);
+        context.setRebooted(true);
+        context.setUpdatedRoles(true);
+        context.setAddTagsComplete(true);
+
+        test_handleRequest_base(
+                context,
+                null,
+                () -> RESOURCE_MODEL_BAREBONE_BLDR()
+                        .automaticBackupReplicationRegion("clearlyNotAValidRegion")
+                        .build(),
+                expectFailed(HandlerErrorCode.InvalidRequest)
+        );
+    }
+
+    @Test
+    public void invalidSourceDBInstanceIdentifierRegion() {
+        expectServiceInvocation = false;
+        final CallbackContext context = new CallbackContext();
+        context.setCreated(true);
+        context.setUpdated(true);
+        context.setRebooted(true);
+        context.setUpdatedRoles(true);
+        context.setAddTagsComplete(true);
+
+        test_handleRequest_base(
+                context,
+                null,
+                () -> RESOURCE_MODEL_BAREBONE_BLDR()
+                        .sourceDBInstanceIdentifier("arn:aws:rds:clearlyNotAValidRegion:340834135580:db:databaseName")
+                        .build(),
+                expectFailed(HandlerErrorCode.InvalidRequest)
+        );
+    }
+
+    @Test
+    public void invalidSourceDBClusterIdentifierRegion() {
+        expectServiceInvocation = false;
+        final CallbackContext context = new CallbackContext();
+        context.setCreated(true);
+        context.setUpdated(true);
+        context.setRebooted(true);
+        context.setUpdatedRoles(true);
+        context.setAddTagsComplete(true);
+
+        test_handleRequest_base(
+                context,
+                null,
+                () -> RESOURCE_MODEL_BAREBONE_BLDR()
+                        .sourceDBClusterIdentifier("arn:aws:rds:clearlyNotAValidRegion:340834135580:cluster:clusterName")
+                        .build(),
+                expectFailed(HandlerErrorCode.InvalidRequest)
+        );
+    }
 }