diff --git a/litellm/proxy/proxy_server.py b/litellm/proxy/proxy_server.py
index 923f41fa30c..757b0b9654a 100644
--- a/litellm/proxy/proxy_server.py
+++ b/litellm/proxy/proxy_server.py
@@ -12624,7 +12624,11 @@ async def get_config():  # noqa: PLR0915
                     _value = os.getenv("SLACK_WEBHOOK_URL", None)
                     _slack_env_vars[_var] = _value
                 else:
-                    _slack_env_vars[_var] = env_variable
+                    _slack_env_vars[_var] = decrypt_value_helper(
+                        value=env_variable,
+                        key=_var,
+                        return_original_value=True,
+                    )
 
             _alerting_types = proxy_logging_obj.slack_alerting_instance.alert_types
             _all_alert_types = (
@@ -12658,7 +12662,16 @@ async def get_config():  # noqa: PLR0915
             if env_variable is None:
                 _email_env_vars[_var] = None
             else:
-                _email_env_vars[_var] = env_variable
+                # Use return_original_value=True so this works for both:
+                # - DB mode: values already decrypted by _update_config_from_db → decryption
+                #   fails gracefully and returns the original plaintext value
+                # - YAML mode: values still encrypted in config file → decrypted here
+                _decrypted_value = decrypt_value_helper(
+                    value=env_variable,
+                    key=_var,
+                    return_original_value=True,
+                )
+                _email_env_vars[_var] = _decrypted_value
 
         alerting_data.append(
             {
diff --git a/tests/proxy_unit_tests/test_proxy_server.py b/tests/proxy_unit_tests/test_proxy_server.py
index 85faea8accc..6b376c0d3c2 100644
--- a/tests/proxy_unit_tests/test_proxy_server.py
+++ b/tests/proxy_unit_tests/test_proxy_server.py
@@ -2726,6 +2726,10 @@ async def test_get_config_callbacks_email_and_slack_values_are_not_decrypted_aga
 ):
     """
     Test that /get/config/callbacks returns already-decrypted email/slack values as-is.
+
+    decrypt_value_helper is called with return_original_value=True, so for already-plaintext
+    values (DB mode: decrypted by _update_config_from_db) it returns the original value
+    unchanged. For encrypted values (YAML mode) it properly decrypts them.
     """
     mock_config_data = {
         "litellm_settings": {},
@@ -2745,10 +2749,15 @@ async def test_get_config_callbacks_email_and_slack_values_are_not_decrypted_aga
 
     proxy_config = getattr(litellm.proxy.proxy_server, "proxy_config")
 
+    # Simulate return_original_value=True behaviour: return the value as-is (already plaintext)
+    def fake_decrypt(value, key, return_original_value=False, **kwargs):
+        return value
+
     with patch.object(
         proxy_config, "get_config", new=AsyncMock(return_value=mock_config_data)
     ), patch(
         "litellm.proxy.proxy_server.decrypt_value_helper",
+        side_effect=fake_decrypt,
     ) as decrypt_mock:
         response = client_no_auth.get("/get/config/callbacks")
 
@@ -2774,7 +2783,8 @@ async def test_get_config_callbacks_email_and_slack_values_are_not_decrypted_aga
         "EMAIL_LOGO_URL": "https://example.com/logo.png",
         "EMAIL_SUPPORT_CONTACT": "support@example.com",
     }
-    decrypt_mock.assert_not_called()
+    # decrypt_value_helper is called once per SMTP var + once for SLACK_WEBHOOK_URL
+    assert decrypt_mock.call_count == len(mock_config_data["environment_variables"])
 
 
 @pytest.mark.asyncio