diff --git a/Lib/httplib.py b/Lib/httplib.py

index 60a8fb4..1b41c34 100644

--- a/Lib/httplib.py

+++ b/Lib/httplib.py

@@ -247,6 +247,16 @@ _MAXHEADERS = 100

 _is_legal_header_name = re.compile(r'\A[^:\s][^:\r\n]*\Z').match

 _is_illegal_header_value = re.compile(r'\n(?![ \t])|\r(?![ \t\n])').search

+# These characters are not allowed within HTTP URL paths.

+#  See https://tools.ietf.org/html/rfc3986#section-3.3 and the

+#  https://tools.ietf.org/html/rfc3986#appendix-A pchar definition.

+# Prevents CVE-2019-9740.  Includes control characters such as \r\n.

+# Restrict non-ASCII characters above \x7f (0x80-0xff).

+_contains_disallowed_url_pchar_re = re.compile('[\x00-\x20\x7f-\xff]')

+# Arguably only these _should_ allowed:

+#  _is_allowed_url_pchars_re = re.compile(r"^[/!$&'()*+,;=:@%a-zA-Z0-9._~-]+$")

+# We are more lenient for assumed real world compatibility purposes.

+

 # We always set the Content-Length header for these methods because some

 # servers will otherwise respond with a 411

 _METHODS_EXPECTING_BODY = {'PATCH', 'POST', 'PUT'}

@@ -927,6 +937,12 @@ class HTTPConnection:

         self._method = method

         if not url:

             url = '/'

+        # Prevent CVE-2019-9740.

+        match = _contains_disallowed_url_pchar_re.search(url)

+        if match:

+            raise InvalidURL("URL can't contain control characters. %r "

+                             "(found at least %r)"

+                             % (url, match.group()))

         hdr = '%s %s %s' % (method, url, self._http_vsn_str)

         self._output(hdr)

diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py

index 1ce9201..d7778d4 100644

--- a/Lib/test/test_urllib.py

+++ b/Lib/test/test_urllib.py

@@ -257,6 +257,31 @@ class urlopen_HttpTests(unittest.TestCase, FakeHTTPMixin):

         finally:

             self.unfakehttp()

+    def test_url_with_control_char_rejected(self):

+        for char_no in range(0, 0x21) + range(0x7f, 0x100):

+            char = chr(char_no)

+            schemeless_url = "//localhost:7777/test%s/" % char

+            self.fakehttp(b"HTTP/1.1 200 OK\r\n\r\nHello.")

+            try:

+                # urllib quotes the URL so there is no injection.

+                resp = urllib.urlopen("http:" + schemeless_url)

+                self.assertNotIn(char, resp.geturl())

+            finally:

+                self.unfakehttp()

+

+    def test_url_with_newline_header_injection_rejected(self):

+        self.fakehttp(b"HTTP/1.1 200 OK\r\n\r\nHello.")

+        host = "localhost:7777?a=1 HTTP/1.1\r\nX-injected: header\r\nTEST: 123"

+        schemeless_url = "//" + host + ":8080/test/?test=a"

+        try:

+            # urllib quotes the URL so there is no injection.

+            resp = urllib.urlopen("http:" + schemeless_url)

+            self.assertNotIn(' ', resp.geturl())

+            self.assertNotIn('\r', resp.geturl())

+            self.assertNotIn('\n', resp.geturl())

+        finally:

+            self.unfakehttp()

+

     def test_read_bogus(self):

         # urlopen() should raise IOError for many error codes.

         self.fakehttp('''HTTP/1.1 401 Authentication Required

diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py

index 6d24d5d..9531818 100644

--- a/Lib/test/test_urllib2.py

+++ b/Lib/test/test_urllib2.py

@@ -15,6 +15,9 @@ try:

 except ImportError:

     ssl = None

+from test.test_urllib import FakeHTTPMixin

+

+

 # XXX

 # Request

 # CacheFTPHandler (hard to write)

@@ -1262,7 +1265,7 @@ class HandlerTests(unittest.TestCase):

         self.assertEqual(len(http_handler.requests), 1)

         self.assertFalse(http_handler.requests[0].has_header(auth_header))

-class MiscTests(unittest.TestCase):

+class MiscTests(unittest.TestCase, FakeHTTPMixin):

     def test_build_opener(self):

         class MyHTTPHandler(urllib2.HTTPHandler): pass

@@ -1317,6 +1320,52 @@ class MiscTests(unittest.TestCase):

             "Unsupported digest authentication algorithm 'invalid'"

         )

+    @unittest.skipUnless(ssl, "ssl module required")

+    def test_url_with_control_char_rejected(self):

+        for char_no in range(0, 0x21) + range(0x7f, 0x100):

+            char = chr(char_no)

+            schemeless_url = "//localhost:7777/test%s/" % char

+            self.fakehttp(b"HTTP/1.1 200 OK\r\n\r\nHello.")

+            try:

+                # We explicitly test urllib.request.urlopen() instead of the top

+                # level 'def urlopen()' function defined in this... (quite ugly)

+                # test suite.  They use different url opening codepaths.  Plain

+                # urlopen uses FancyURLOpener which goes via a codepath that

+                # calls urllib.parse.quote() on the URL which makes all of the

+                # above attempts at injection within the url _path_ safe.

+                escaped_char_repr = repr(char).replace('\\', r'\\')

+                InvalidURL = httplib.InvalidURL

+                with self.assertRaisesRegexp(

+                    InvalidURL, "contain control.*" + escaped_char_repr):

+                    urllib2.urlopen("http:" + schemeless_url)

+                with self.assertRaisesRegexp(

+                    InvalidURL, "contain control.*" + escaped_char_repr):

+                    urllib2.urlopen("https:" + schemeless_url)

+            finally:

+                self.unfakehttp()

+

+    @unittest.skipUnless(ssl, "ssl module required")

+    def test_url_with_newline_header_injection_rejected(self):

+        self.fakehttp(b"HTTP/1.1 200 OK\r\n\r\nHello.")

+        host = "localhost:7777?a=1 HTTP/1.1\r\nX-injected: header\r\nTEST: 123"

+        schemeless_url = "//" + host + ":8080/test/?test=a"

+        try:

+            # We explicitly test urllib2.urlopen() instead of the top

+            # level 'def urlopen()' function defined in this... (quite ugly)

+            # test suite.  They use different url opening codepaths.  Plain

+            # urlopen uses FancyURLOpener which goes via a codepath that

+            # calls urllib.parse.quote() on the URL which makes all of the

+            # above attempts at injection within the url _path_ safe.

+            InvalidURL = httplib.InvalidURL

+            with self.assertRaisesRegexp(

+                InvalidURL, r"contain control.*\\r.*(found at least . .)"):

+                urllib2.urlopen("http:" + schemeless_url)

+            with self.assertRaisesRegexp(InvalidURL, r"contain control.*\\n"):

+                urllib2.urlopen("https:" + schemeless_url)

+        finally:

+            self.unfakehttp()

+

+

 class RequestTests(unittest.TestCase):

diff --git a/Lib/test/test_xmlrpc.py b/Lib/test/test_xmlrpc.py

index 36b3be6..90ccb30 100644

--- a/Lib/test/test_xmlrpc.py

+++ b/Lib/test/test_xmlrpc.py

@@ -659,7 +659,13 @@ class SimpleServerTestCase(BaseServerTestCase):

     def test_partial_post(self):

         # Check that a partial POST doesn't make the server loop: issue #14001.

         conn = httplib.HTTPConnection(ADDR, PORT)

-        conn.request('POST', '/RPC2 HTTP/1.0\r\nContent-Length: 100\r\n\r\nbye')

+        conn.send('POST /RPC2 HTTP/1.0\r\n'

+                  'Content-Length: 100\r\n\r\n'

+                  'bye HTTP/1.1\r\n'

+                  'Host: %s:%s\r\n'

+                  'Accept-Encoding: identity\r\n'

+                  'Content-Length: 0\r\n\r\n'

+                  % (ADDR, PORT))

         conn.close()

 class SimpleServerEncodingTestCase(BaseServerTestCase):