validate trusted_hosts during routing

CHANGES.rst

@@ -9,6 +9,9 @@ Unreleased
     matching. In ``bind_to_environ``, the ``server_name`` parameter is not used
     if ``host_matching`` is enabled. If ``default_subdomain`` is set, it is used
     if a subdomain could not be determined. :issue:`3005`
+-   If a request object is passed to ``Map.bind_to_environ``, the host is
+    validated against ``request.trusted_hosts``. An invalid host will raise a
+    400 error. :issue:`3007`
 
 
 Version 3.1.3

src/werkzeug/routing/map.py

@@ -16,6 +16,7 @@
 from ..exceptions import HTTPException
 from ..exceptions import MethodNotAllowed
 from ..exceptions import NotFound
+from ..sansio.request import Request as SansIORequest
 from ..urls import _urlencode
 from ..wsgi import get_host
 from .converters import DEFAULT_CONVERTERS
@@ -278,7 +279,9 @@ def bind_to_environ(
         ``"<invalid>"`` is used.
 
         :param environ: The WSGI environ for the request. Can also be a
-            ``Request`` with an ``environ`` attribute.
+            ``Request`` with an ``environ`` attribute; in that case, its
+            :attr:`~.Request.host` is accessed to validate its
+            :attr:`~.Request.trusted_hosts`.
         :param server_name: When subdomain matching is enabled and ``subdomain``
             is not given, the subdomain is determined by removing this
             ``host:port`` as a suffix from the request's ``Host``. If the scheme
@@ -298,6 +301,10 @@ def bind_to_environ(
         .. versionchanged:: 3.2
             ``server_name`` is ignored if ``host_matching`` is enabled.
 
+        .. versionchanged:: 3.2
+            If the ``environ`` argument is a ``Request``, access ``request.host``
+            to validate``request.trusted_hosts``.
+
         .. versionchanged:: 1.0.0
             If ``server_name`` specifies port 443, it will match if the scheme
             is ``https`` and ``Host`` does not specify a port.
@@ -312,8 +319,12 @@ def bind_to_environ(
         .. versionchanged:: 0.5
             Removed the ``calculate_subdomain`` parameter which was not used.
         """
+        if isinstance(environ, SansIORequest):
+            wsgi_server_name = environ.host.lower()
+        else:
+            wsgi_server_name = get_host(environ).lower()
+
         env = _get_environ(environ)
-        wsgi_server_name = get_host(env).lower()
         scheme = env["wsgi.url_scheme"]
         upgrade = any(
             v.strip() == "upgrade"