fix(proxy): keep stored user_email when SSO login carries no email claim

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/proxy/management_endpoints/ui_sso.py

@@ -1894,11 +1894,12 @@ def _build_sso_user_update_data(
         existing_user_alias: The user's current alias in the DB; only an empty alias is filled from SSO
 
     Returns:
-        dict: Update data containing user_email, user_alias when newly available, and user_role if valid
+        dict: Update data containing user_email and user_alias when the IdP supplied them, and user_role if valid
     """
+    sso_user_email: Final = normalize_email(user_email)
     sso_user_alias: Final = None if existing_user_alias else _get_sso_user_alias(result)
     update_data: Final[dict[str, object]] = {
-        "user_email": normalize_email(user_email),
+        **({"user_email": sso_user_email} if sso_user_email is not None else {}),
         **({"user_alias": sso_user_alias} if sso_user_alias is not None else {}),
     }
 
@@ -3284,6 +3285,7 @@ class SSOAuthenticationHandler:
                     existing_user_alias=user_info.user_alias if isinstance(user_info, LiteLLM_UserTable) else None,
                 )
 
+                if update_data:
                     await _user_meta_db(UserRepository(prisma_client)).update_many(
                         where={"user_id": user_id}, data=update_data
                     )

tests/unit/proxy/management_endpoints/test_ui_sso.py

@@ -1141,6 +1141,63 @@ async def test_upsert_sso_user_fills_user_alias_for_existing_user():
     )
 
 
+def test_build_sso_user_update_data_omits_email_when_idp_sends_none():
+    """
+    A login without an email claim must not write user_email, so a stored email survives.
+    """
+    from litellm.proxy.management_endpoints.types import CustomOpenID
+    from litellm.proxy.management_endpoints.ui_sso import _build_sso_user_update_data
+
+    sso_result = CustomOpenID(
+        id="S-1-5-21-adfs-user",
+        email=None,
+        display_name="Doe, Jane",
+        provider="generic",
+        team_ids=[],
+    )
+
+    update_data = _build_sso_user_update_data(
+        result=sso_result,
+        user_email=None,
+        user_id="S-1-5-21-adfs-user",
+        existing_user_alias=None,
+    )
+
+    assert update_data == {"user_alias": "Doe, Jane"}
+
+
+@pytest.mark.asyncio
+async def test_upsert_sso_user_keeps_stored_email_when_idp_sends_none():
+    """
+    An existing user whose IdP token carries no email and no new name is left untouched on login.
+    """
+    from litellm.proxy._types import LiteLLM_UserTable
+    from litellm.proxy.management_endpoints.types import CustomOpenID
+    from litellm.proxy.management_endpoints.ui_sso import SSOAuthenticationHandler
+
+    mock_prisma = MagicMock()
+    mock_prisma.db.litellm_usertable.update_many = AsyncMock()
+
+    existing_user = LiteLLM_UserTable(
+        user_id="S-1-5-21-adfs-user",
+        user_email="admin.typed@example.com",
+        user_role="internal_user",
+        user_alias="Doe, Jane",
+    )
+    sso_result = CustomOpenID(id="S-1-5-21-adfs-user", email=None, provider="generic", team_ids=[])
+
+    returned = await SSOAuthenticationHandler.upsert_sso_user(
+        result=sso_result,
+        user_info=existing_user,
+        user_email=None,
+        user_defined_values=None,
+        prisma_client=mock_prisma,
+    )
+
+    assert returned is existing_user
+    mock_prisma.db.litellm_usertable.update_many.assert_not_called()
+
+
 @pytest.mark.asyncio
 async def test_insert_sso_user_sets_user_alias_from_display_name():
     """