From db966c03263943dc718f01252ee756be836d129d Mon Sep 17 00:00:00 2001
From: Robin Siep <RobinSiep1@gmail.com>
Date: Fri, 11 Sep 2026 17:37:31 +0200
Subject: [PATCH] Fix reauth flow possibly pointing to different UniFi site
 (#180936)

---
 homeassistant/components/unifi/config_flow.py | 16 ++++----
 homeassistant/components/unifi/strings.json   |  3 +-
 tests/components/unifi/test_config_flow.py    | 38 +++++++++++++++++++
 3 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/homeassistant/components/unifi/config_flow.py b/homeassistant/components/unifi/config_flow.py
index 632d21e0a853..5aa33f6c0a77 100644
--- a/homeassistant/components/unifi/config_flow.py
+++ b/homeassistant/components/unifi/config_flow.py
@@ -31,7 +31,7 @@ from homeassistant.const import (
     CONF_VERIFY_SSL,
 )
 from homeassistant.core import HomeAssistant, callback
-from homeassistant.data_entry_flow import SectionConfig, section
+from homeassistant.data_entry_flow import AbortFlow, SectionConfig, section
 from homeassistant.helpers import config_validation as cv
 from homeassistant.helpers.device_registry import format_mac
 from homeassistant.helpers.typing import DiscoveryInfoType
@@ -113,15 +113,15 @@ class UnifiFlowHandler(ConfigFlow, domain=DOMAIN):
                 errors["base"] = "service_unavailable"
 
             else:
-                if (
-                    self.source == SOURCE_REAUTH
-                    and (
+                if self.source == SOURCE_REAUTH:
+                    if (
                         (reauth_unique_id := self._get_reauth_entry().unique_id)
                         is not None
-                    )
-                    and reauth_unique_id in self.sites
-                ):
-                    return await self.async_step_site({CONF_SITE_ID: reauth_unique_id})
+                    ) and reauth_unique_id in self.sites:
+                        return await self.async_step_site(
+                            {CONF_SITE_ID: reauth_unique_id}
+                        )
+                    raise AbortFlow("unknown_site_id")
 
                 return await self.async_step_site()
 
diff --git a/homeassistant/components/unifi/strings.json b/homeassistant/components/unifi/strings.json
index b3bf482edfc5..c44b2d9c5260 100644
--- a/homeassistant/components/unifi/strings.json
+++ b/homeassistant/components/unifi/strings.json
@@ -4,7 +4,8 @@
       "already_configured": "UniFi Network site is already configured",
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
       "configuration_updated": "Configuration updated",
-      "reauth_successful": "[%key:common::config_flow::abort::reauth_successful%]"
+      "reauth_successful": "[%key:common::config_flow::abort::reauth_successful%]",
+      "unknown_site_id": "Previously configured UniFi Network site can no longer be found"
     },
     "error": {
       "faulty_credentials": "[%key:common::config_flow::error::invalid_auth%]",
diff --git a/tests/components/unifi/test_config_flow.py b/tests/components/unifi/test_config_flow.py
index 1e4632fa137d..3d82f891996a 100644
--- a/tests/components/unifi/test_config_flow.py
+++ b/tests/components/unifi/test_config_flow.py
@@ -1,5 +1,6 @@
 """Test UniFi Network config flow."""
 
+from collections.abc import Callable
 import socket
 from typing import Any
 from unittest.mock import PropertyMock, patch
@@ -386,6 +387,43 @@ async def test_reauth_flow_update_configuration_on_not_loaded_entry(
     assert config_entry.data[CONF_PASSWORD] == "new_pass"
 
 
+@pytest.mark.parametrize(
+    "site_payload",
+    [
+        [
+            {"name": "site2", "role": "admin", "desc": "site2 name", "_id": "2"},
+        ]
+    ],
+)
+async def test_abort_reauth_flow_on_site_id_mismatch(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+    mock_requests: Callable[[str, str], None],
+) -> None:
+    """Verify reauth flow aborts when original site can no longer be found."""
+    mock_requests(config_entry.data[CONF_HOST], config_entry.data[CONF_SITE_ID])
+
+    result = await config_entry.start_reauth_flow(hass)
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "user"
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        user_input={
+            CONF_HOST: "1.2.3.4",
+            CONF_USERNAME: "new_name",
+            CONF_PASSWORD: "new_pass",
+            CONF_PORT: 1234,
+            CONF_VERIFY_SSL: True,
+        },
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "unknown_site_id"
+    assert config_entry.data[CONF_SITE_ID] == "site_id"
+
+
 @pytest.mark.parametrize("client_payload", [CLIENTS])
 @pytest.mark.parametrize("device_payload", [DEVICES])
 @pytest.mark.parametrize("wlan_payload", [WLANS])