diff --git a/cloudinit/sources/DataSourceDigitalOcean.py b/cloudinit/sources/DataSourceDigitalOcean.py
index b4856011431..ddd3310892e 100644
--- a/cloudinit/sources/DataSourceDigitalOcean.py
+++ b/cloudinit/sources/DataSourceDigitalOcean.py
@@ -110,7 +110,7 @@ def network_config(self):
         migration.
         """
 
-        if self._network_config:
+        if self._network_config and self._network_config != sources.UNSET:
             return self._network_config
 
         interfaces = self.metadata.get("interfaces")
diff --git a/cloudinit/sources/DataSourceUpCloud.py b/cloudinit/sources/DataSourceUpCloud.py
index 618052086dc..62304b117c3 100644
--- a/cloudinit/sources/DataSourceUpCloud.py
+++ b/cloudinit/sources/DataSourceUpCloud.py
@@ -115,7 +115,7 @@ def network_config(self):
         due to reconfiguration.
         """
 
-        if self._network_config:
+        if self._network_config and self._network_config != sources.UNSET:
             return self._network_config
 
         raw_network_config = self.metadata.get("network")
diff --git a/tests/unittests/sources/test_digitalocean.py b/tests/unittests/sources/test_digitalocean.py
index a99718b9ba5..57d94e28307 100644
--- a/tests/unittests/sources/test_digitalocean.py
+++ b/tests/unittests/sources/test_digitalocean.py
@@ -12,7 +12,7 @@
 
 import pytest
 
-from cloudinit import settings
+from cloudinit import settings, sources
 from cloudinit.sources import DataSourceDigitalOcean
 from cloudinit.sources.helpers import digitalocean
 
@@ -248,6 +248,35 @@ def test_multiple_ssh_keys(self, mock_readmd, get_ds):
         assert metadata["public_keys"] == ds.get_public_ssh_keys()
         assert isinstance(ds.get_public_ssh_keys(), list)
 
+    @mock.patch("cloudinit.net.get_interfaces_by_mac")
+    @mock.patch("cloudinit.sources.helpers.digitalocean.read_metadata")
+    def test_network_config_unset_recomputes(
+        self, mock_readmd, m_get_by_mac, get_ds
+    ):
+        """GH-7067: network_config must recompute when
+        _network_config is UNSET.
+
+        update_metadata_if_supported() sets _network_config = sources.UNSET
+        (the truthy string "_unset"). Without the UNSET sentinel check, the
+        bare truthiness guard returns the sentinel directly instead of
+        recomputing, causing AttributeError in apply_network_config.
+        """
+        mock_readmd.return_value = DO_META.copy()
+        m_get_by_mac.return_value = {
+            "04:01:57:d1:9e:01": "eth0",
+            "04:01:57:d1:9e:02": "eth1",
+        }
+
+        ds = get_ds()
+        assert ds.get_data() is True
+
+        # Simulate what update_metadata_if_supported() does on every boot
+        ds._network_config = sources.UNSET
+        recomputed_netcfg = ds.network_config
+        assert recomputed_netcfg != sources.UNSET
+        assert isinstance(recomputed_netcfg, dict)
+        assert "config" in recomputed_netcfg
+
 
 class TestNetworkConvert:
     def _get_networking(self):
diff --git a/tests/unittests/sources/test_upcloud.py b/tests/unittests/sources/test_upcloud.py
index 68bff97cd04..80bd79df96c 100644
--- a/tests/unittests/sources/test_upcloud.py
+++ b/tests/unittests/sources/test_upcloud.py
@@ -278,6 +278,39 @@ def test_network_configuration(self, m_get_by_mac, mock_readmd, ds):
             UC_METADATA.get("network").get("dns")[1] == dns.get("address")[1]
         )
 
+    @mock.patch("cloudinit.sources.helpers.upcloud.read_metadata")
+    @mock.patch("cloudinit.net.get_interfaces_by_mac")
+    def test_network_config_unset_recomputes(
+        self, m_get_by_mac, mock_readmd, ds
+    ):
+        """GH-7067: network_config must recompute when
+        _network_config is UNSET.
+
+        update_metadata_if_supported() sets _network_config = sources.UNSET
+        (the truthy string "_unset"). Without the UNSET sentinel check, the
+        bare truthiness guard returns the sentinel directly instead of
+        recomputing, causing AttributeError in apply_network_config.
+        """
+        mock_readmd.return_value = UC_METADATA.copy()
+
+        raw_ifaces = UC_METADATA.get("network").get("interfaces")
+        m_get_by_mac.return_value = {
+            raw_ifaces[0].get("mac"): "eth0",
+            raw_ifaces[1].get("mac"): "eth1",
+            raw_ifaces[2].get("mac"): "eth2",
+            raw_ifaces[3].get("mac"): "eth3",
+        }
+
+        ds.perform_dhcp_setup = False
+        assert ds.get_data() is True
+
+        # Simulate what update_metadata_if_supported() does
+        ds._network_config = sources.UNSET
+        recomputed_netcfg = ds.network_config
+        assert recomputed_netcfg != sources.UNSET
+        assert isinstance(recomputed_netcfg, dict)
+        assert 1 == recomputed_netcfg.get("version")
+
 
 class TestUpCloudDatasourceLoading:
     def test_get_datasource_list_returns_in_local(self):