diff --git a/osism/commands/vault.py b/osism/commands/vault.py
index 3557a0985..57d7b2ec1 100644
--- a/osism/commands/vault.py
+++ b/osism/commands/vault.py
@@ -67,6 +67,9 @@ def get_parser(self, prog_name):
 
     def take_action(self, parsed_args):
         path = parsed_args.path
+        if path is None:
+            logger.error("No path specified")
+            return 1
         if not os.path.isabs(path):
             path = os.path.join("/opt/configuration", path)
 
@@ -84,9 +87,7 @@ def take_action(self, parsed_args):
             return 1
 
         if content.startswith(b"$ANSIBLE_VAULT"):
-            return subprocess.call(
-                f"/usr/local/bin/ansible-vault view {path}", shell=True
-            )
+            return subprocess.call(["/usr/local/bin/ansible-vault", "view", path])
 
         logger.warning(f"File is not vault-encrypted, showing plain content: {path}")
         sys.stdout.write(content.decode("utf-8", errors="replace"))
@@ -102,9 +103,12 @@ def get_parser(self, prog_name):
 
     def take_action(self, parsed_args):
         path = parsed_args.path
+        if path is None:
+            logger.error("No path specified")
+            return 1
         if not os.path.isabs(path):
             path = os.path.join("/opt/configuration", path)
-        subprocess.call(f"/usr/local/bin/ansible-vault decrypt {path}", shell=True)
+        return subprocess.call(["/usr/local/bin/ansible-vault", "decrypt", path])
 
 
 # Well-known paths where secrets.yml files are typically found
diff --git a/tests/unit/commands/test_vault.py b/tests/unit/commands/test_vault.py
index c97caf825..de50a09e7 100644
--- a/tests/unit/commands/test_vault.py
+++ b/tests/unit/commands/test_vault.py
@@ -26,7 +26,7 @@ def test_view_invokes_ansible_vault_for_encrypted_file(tmp_path):
         _make_view().take_action(parsed_args)
 
     mock_call.assert_called_once_with(
-        f"/usr/local/bin/ansible-vault view {path}", shell=True
+        ["/usr/local/bin/ansible-vault", "view", str(path)]
     )
 
 
@@ -59,7 +59,7 @@ def test_view_resolves_relative_path_against_opt_configuration():
     expected = "/opt/configuration/environments/openstack/secure.yml"
     open_mock.assert_called_once_with(expected, "rb")
     mock_call.assert_called_once_with(
-        f"/usr/local/bin/ansible-vault view {expected}", shell=True
+        ["/usr/local/bin/ansible-vault", "view", expected]
     )
 
 
@@ -108,5 +108,63 @@ def test_view_invokes_ansible_vault_for_vault_variants(tmp_path, header):
         _make_view().take_action(parsed_args)
 
     mock_call.assert_called_once_with(
-        f"/usr/local/bin/ansible-vault view {path}", shell=True
+        ["/usr/local/bin/ansible-vault", "view", str(path)]
     )
+
+
+def test_view_requires_path(loguru_logs):
+    parser = _make_view().get_parser("test")
+    parsed_args = parser.parse_args([])
+
+    with patch("osism.commands.vault.subprocess.call") as mock_call:
+        rc = _make_view().take_action(parsed_args)
+
+    assert rc == 1
+    mock_call.assert_not_called()
+    errors = [r for r in loguru_logs if r["level"] == "ERROR"]
+    assert any("No path" in r["message"] for r in errors)
+
+
+# --- Decrypt.take_action ---
+
+
+def test_decrypt_requires_path(loguru_logs):
+    cmd = vault.Decrypt(MagicMock(), MagicMock())
+    parser = cmd.get_parser("test")
+    parsed_args = parser.parse_args([])
+
+    with patch("osism.commands.vault.subprocess.call") as mock_call:
+        rc = cmd.take_action(parsed_args)
+
+    assert rc == 1
+    mock_call.assert_not_called()
+    errors = [r for r in loguru_logs if r["level"] == "ERROR"]
+    assert any("No path" in r["message"] for r in errors)
+
+
+def test_decrypt_invokes_ansible_vault_without_shell(tmp_path):
+    path = tmp_path / "secrets.yml"
+    path.write_bytes(b"$ANSIBLE_VAULT;1.1;AES256\nciphertext\n")
+    cmd = vault.Decrypt(MagicMock(), MagicMock())
+    parser = cmd.get_parser("test")
+    parsed_args = parser.parse_args([str(path)])
+
+    with patch("osism.commands.vault.subprocess.call") as mock_call:
+        cmd.take_action(parsed_args)
+
+    mock_call.assert_called_once_with(
+        ["/usr/local/bin/ansible-vault", "decrypt", str(path)]
+    )
+
+
+def test_decrypt_propagates_exit_code(tmp_path):
+    path = tmp_path / "secrets.yml"
+    path.write_bytes(b"$ANSIBLE_VAULT;1.1;AES256\nciphertext\n")
+    cmd = vault.Decrypt(MagicMock(), MagicMock())
+    parser = cmd.get_parser("test")
+    parsed_args = parser.parse_args([str(path)])
+
+    with patch("osism.commands.vault.subprocess.call", return_value=1):
+        rc = cmd.take_action(parsed_args)
+
+    assert rc == 1