diff --git a/django/contrib/auth/__init__.py b/django/contrib/auth/__init__.py
index 723f348824fc..1d7199ce471c 100644
--- a/django/contrib/auth/__init__.py
+++ b/django/contrib/auth/__init__.py
@@ -402,6 +402,7 @@ def check_password_with_timing_attack_mitigation(user, password):
 async def acheck_password_with_timing_attack_mitigation(user, password):
     """See check_user_with_timing_attack_mitigation."""
     if user is None:
-        await sync_to_async(get_user_model()().set_password)(password)
+        set_password = get_user_model()().set_password
+        await sync_to_async(set_password, thread_sensitive=False)(password)
     else:
         return await user.acheck_password(password)
diff --git a/django/http/request.py b/django/http/request.py
index 44bf09450bb4..28208d57a995 100644
--- a/django/http/request.py
+++ b/django/http/request.py
@@ -404,10 +404,16 @@ def body(self):
                     "You cannot access body after reading from request's data stream"
                 )
 
+            # Make Content-Length fall back to 0 if malformed (e.g. ASGIRequest
+            # comma-joins duplicate Content-Length headers).
+            try:
+                content_length = int(self.META.get("CONTENT_LENGTH") or 0)
+            except (ValueError, TypeError):
+                content_length = 0
             # Limit the maximum request data size that will be handled
             # in-memory. Reject early when Content-Length is present and
             # already exceeds the limit, avoiding reading the body at all.
-            self._check_data_too_big(int(self.META.get("CONTENT_LENGTH") or 0))
+            self._check_data_too_big(content_length)
 
             # Content-Length can be absent or understated (e.g.
             # `Transfer-Encoding: chunked` on ASGI), so for seekable
diff --git a/tests/asgi/tests.py b/tests/asgi/tests.py
index 1ff68920782e..727ce2fa6c91 100644
--- a/tests/asgi/tests.py
+++ b/tests/asgi/tests.py
@@ -804,6 +804,24 @@ def test_multiple_cookie_headers_http2(self):
                 self.assertEqual(request.META["HTTP_COOKIE"], "a=abc; b=def; c=ghi")
                 self.assertEqual(request.COOKIES, {"a": "abc", "b": "def", "c": "ghi"})
 
+    def test_malformed_content_length(self):
+        body = b"hello world body"
+        cases = [
+            {"content_length_headers": [b"10", b"20"], "CONTENT_LENGTH": "10,20"},
+            {"content_length_headers": [b"abc"], "CONTENT_LENGTH": "abc"},
+        ]
+        for case in cases:
+            with self.subTest(CONTENT_LENGTH=case["CONTENT_LENGTH"]):
+                scope = self.async_request_factory._base_scope(method="POST", path="/")
+                headers = [(b"content-type", b"text/plain")]
+                for content_length in case["content_length_headers"]:
+                    headers.append((b"content-length", content_length))
+                scope["headers"] = headers
+                request = ASGIRequest(scope, BytesIO(body))
+                self.assertEqual(dict(request.POST), {})
+                self.assertEqual(request.body, body)
+                self.assertEqual(request.META["CONTENT_LENGTH"], case["CONTENT_LENGTH"])
+
 
 class MaxMemorySizeASGITests(SimpleTestCase):
     def make_request(
@@ -832,6 +850,22 @@ def test_body_size_exceeded_without_content_length(self):
         ):
             request.body
 
+    def test_body_size_exceeded_with_malformed_content_length(self):
+        body = b"x" * 10
+        scope = AsyncRequestFactory()._base_scope(method="POST", path="/")
+        scope["headers"] = [
+            (b"content-type", b"application/octet-stream"),
+            (b"content-length", b"10"),
+            (b"content-length", b"20"),
+        ]
+        request = ASGIRequest(scope, BytesIO(body))
+        self.assertEqual(request.META["CONTENT_LENGTH"], "10,20")
+        with (
+            self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=5),
+            self.assertRaisesMessage(RequestDataTooBig, TOO_MUCH_DATA_MSG),
+        ):
+            request.body
+
     def test_body_size_check_fires_before_read(self):
         # The seekable size check rejects oversized bodies before reading
         # them into memory (i.e. before calling self.read()).