diff --git a/cheroot/server.py b/cheroot/server.py
index 284cf17c72..92652d1b24 100644
--- a/cheroot/server.py
+++ b/cheroot/server.py
@@ -800,6 +800,13 @@ def read_request_line(self):  # noqa: C901  # FIXME
             )
             return False
 
+        if b'\x00' in request_line:
+            self.simple_response(
+                '400 Bad Request',
+                'Malformed Request-Line',
+            )
+            return False
+
         try:
             method, uri, req_protocol = request_line.strip().split(SPACE, 2)
             if not req_protocol.startswith(b'HTTP/'):
diff --git a/cheroot/test/test_core.py b/cheroot/test/test_core.py
index cd3841d428..b0e039720c 100644
--- a/cheroot/test/test_core.py
+++ b/cheroot/test/test_core.py
@@ -314,6 +314,11 @@ def test_large_request(test_client_with_defaults):
             HTTP_BAD_REQUEST,
             b'Malformed Request-Line',
         ),
+        (
+            b'GET /\x00 HTTP/1.1',  # NUL byte
+            HTTP_BAD_REQUEST,
+            b'Malformed Request-Line',
+        ),
         (
             b'GET / HTTPS/1.1',  # invalid proto
             HTTP_BAD_REQUEST,
diff --git a/docs/changelog-fragments.d/832.bugfix.rst b/docs/changelog-fragments.d/832.bugfix.rst
new file mode 100644
index 0000000000..c554cbfba3
--- /dev/null
+++ b/docs/changelog-fragments.d/832.bugfix.rst
@@ -0,0 +1 @@
+Rejected HTTP request lines containing NUL bytes as malformed requests.