@@ -311,6 +311,9 @@ or on combining URL components into a URL string.

``#``, ``@``, or ``:`` will raise a :exc:`ValueError`. If the URL is

decomposed before parsing, no error will be raised.

Following the `WHATWG spec`_ that updates RFC 3986, ASCII newline

``\n``, ``\r`` and tab ``\t`` characters are stripped from the URL.

.. versionchanged:: 3.6

Out-of-range port numbers now raise :exc:`ValueError`, instead of

returning :const:`None`.

@@ -319,6 +322,10 @@ or on combining URL components into a URL string.

Characters that affect netloc parsing under NFKC normalization will

now raise :exc:`ValueError`.

.. versionchanged:: 3.9.5

ASCII newline and tab characters are stripped from the URL.

.. _WHATWG spec: https://url.spec.whatwg.org/#concept-basic-url-parser

.. function:: urlunsplit(parts)

@@ -673,6 +680,10 @@ task isn't already covered by the URL parsing functions above.

.. seealso::

`WHATWG`_ - URL Living standard

Working Group for the URL Standard that defines URLs, domains, IP addresses, the

application/x-www-form-urlencoded format, and their API.

:rfc:`3986` - Uniform Resource Identifiers

This is the current standard (STD66). Any changes to urllib.parse module

should conform to this. Certain deviations could be observed, which are

@@ -696,3 +707,5 @@ task isn't already covered by the URL parsing functions above.

:rfc:`1738` - Uniform Resource Locators (URL)

This specifies the formal syntax and semantics of absolute URLs.

.. _WHATWG: https://url.spec.whatwg.org/

@@ -612,6 +612,35 @@ def test_urlsplit_attributes(self):

with self.assertRaisesRegex(ValueError, "out of range"):

p.port

def test_urlsplit_remove_unsafe_bytes(self):

# Remove ASCII tabs and newlines from input

url = "http://www.python.org/java\nscript:\talert('msg\r\n')/#frag"

p = urllib.parse.urlsplit(url)

self.assertEqual(p.scheme, "http")

self.assertEqual(p.netloc, "www.python.org")

self.assertEqual(p.path, "/javascript:alert('msg')/")

self.assertEqual(p.query, "")

self.assertEqual(p.fragment, "frag")

self.assertEqual(p.username, None)

self.assertEqual(p.password, None)

self.assertEqual(p.hostname, "www.python.org")

self.assertEqual(p.port, None)

self.assertEqual(p.geturl(), "http://www.python.org/javascript:alert('msg')/#frag")

# Remove ASCII tabs and newlines from input as bytes.

url = b"http://www.python.org/java\nscript:\talert('msg\r\n')/#frag"

p = urllib.parse.urlsplit(url)

self.assertEqual(p.scheme, b"http")

self.assertEqual(p.netloc, b"www.python.org")

self.assertEqual(p.path, b"/javascript:alert('msg')/")

self.assertEqual(p.query, b"")

self.assertEqual(p.fragment, b"frag")

self.assertEqual(p.username, None)

self.assertEqual(p.password, None)

self.assertEqual(p.hostname, b"www.python.org")

self.assertEqual(p.port, None)

self.assertEqual(p.geturl(), b"http://www.python.org/javascript:alert('msg')/#frag")

def test_attributes_bad_port(self):

"""Check handling of invalid ports."""

for bytes in (False, True):

@@ -78,6 +78,9 @@

'0123456789'

'+-.')

# Unsafe bytes to be removed per WHATWG spec

_UNSAFE_URL_BYTES_TO_REMOVE = ['\t', '\r', '\n']

# XXX: Consider replacing with functools.lru_cache

MAX_CACHE_SIZE = 20

_parse_cache = {}

@@ -469,6 +472,9 @@ def urlsplit(url, scheme='', allow_fragments=True):

else:

scheme, url = url[:i].lower(), url[i+1:]

for b in _UNSAFE_URL_BYTES_TO_REMOVE:

url = url.replace(b, "")

if url[:2] == '//':

netloc, url = _splitnetloc(url, 2)

if (('[' in netloc and ']' not in netloc) or

@@ -0,0 +1,6 @@

The presence of newline or tab characters in parts of a URL could allow

some forms of attacks.

Following the controlling specification for URLs defined by WHATWG

:func:`urllib.parse` now removes ASCII newlines and tabs from URLs,

preventing such attacks.