From ac2c88629f548149def2c20868bfbee7744d558f Mon Sep 17 00:00:00 2001
From: Andrew Dang <andrewdang357@gmail.com>
Date: Sat, 27 Jun 2026 01:57:58 -0500
Subject: [PATCH 1/2] Fix 503 request flags in unservicable connections

---
 cheroot/server.py           |  7 ++++-
 cheroot/test/test_server.py | 58 +++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/cheroot/server.py b/cheroot/server.py
index 284cf17c72..8149115f43 100644
--- a/cheroot/server.py
+++ b/cheroot/server.py
@@ -1893,7 +1893,12 @@ def _serve_unservicable(self):
             conn = self._unservicable_conns.get()
             if conn is _STOPPING_FOR_INTERRUPT:
                 return
-            request = HTTPRequest(self, conn)
+            request = HTTPRequest(
+                self,
+                conn,
+                proxy_mode=self.proxy_mode,
+                strict_mode=self.strict_mode,
+            )
             try:
                 request.simple_response('503 Service Unavailable')
             except (OSError, errors.FatalSSLAlert):
diff --git a/cheroot/test/test_server.py b/cheroot/test/test_server.py
index ae6e390a44..d0bfad7915 100644
--- a/cheroot/test/test_server.py
+++ b/cheroot/test/test_server.py
@@ -127,6 +127,64 @@ def test_stop_interrupts_serve():
     assert not serve_thread.is_alive()
 
 
+def test_unservicable_conn_uses_server_proxy_and_strict_mode(monkeypatch):
+    """Check that 503 requests inherit proxy/strict mode from the server."""
+    httpserver = HTTPServer(
+        bind_addr=(ANY_INTERFACE_IPV4, EPHEMERAL_PORT),
+        gateway=Gateway,
+    )
+    close_calls = []
+    request_init_args = []
+
+    class CapturingHTTPRequest:
+        """Capture request constructor args used for 503 responses."""
+
+        def __init__(
+            self,
+            server,
+            conn,
+            proxy_mode=False,
+            strict_mode=True,
+        ):
+            request_init_args.append(
+                {
+                    'server': server,
+                    'conn': conn,
+                    'proxy_mode': proxy_mode,
+                    'strict_mode': strict_mode,
+                },
+            )
+
+        def simple_response(self, _status):
+            return None
+
+    def close_conn():
+        close_calls.append(None)
+
+    conn = types.SimpleNamespace(linger=False, close=close_conn)
+    stopping_sentinel = object()
+    httpserver.proxy_mode = True
+    httpserver.strict_mode = False
+    httpserver.ready = True
+    httpserver._unservicable_conns.put(conn)
+    httpserver._unservicable_conns.put(stopping_sentinel)
+    monkeypatch.setattr('cheroot.server._STOPPING_FOR_INTERRUPT', stopping_sentinel)
+    monkeypatch.setattr('cheroot.server.HTTPRequest', CapturingHTTPRequest)
+
+    httpserver._serve_unservicable()
+
+    assert request_init_args == [
+        {
+            'server': httpserver,
+            'conn': conn,
+            'proxy_mode': True,
+            'strict_mode': False,
+        },
+    ]
+    assert conn.linger is True
+    assert close_calls == [None]
+
+
 @pytest.mark.parametrize(
     'exc_cls',
     (

From a433c69696b5c00972539d12775abafa5a95b4d8 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sat, 27 Jun 2026 07:00:31 +0000
Subject: [PATCH 2/2] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 cheroot/test/test_server.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cheroot/test/test_server.py b/cheroot/test/test_server.py
index d0bfad7915..b7286dafe5 100644
--- a/cheroot/test/test_server.py
+++ b/cheroot/test/test_server.py
@@ -168,7 +168,10 @@ def close_conn():
     httpserver.ready = True
     httpserver._unservicable_conns.put(conn)
     httpserver._unservicable_conns.put(stopping_sentinel)
-    monkeypatch.setattr('cheroot.server._STOPPING_FOR_INTERRUPT', stopping_sentinel)
+    monkeypatch.setattr(
+        'cheroot.server._STOPPING_FOR_INTERRUPT',
+        stopping_sentinel,
+    )
     monkeypatch.setattr('cheroot.server.HTTPRequest', CapturingHTTPRequest)
 
     httpserver._serve_unservicable()