From ac655bc5de633400527d3c4165d9166d41619e3a Mon Sep 17 00:00:00 2001 From: Lumir Balhar Date: Fri, 14 Aug 2026 15:05:08 +0200 Subject: [PATCH] Security fix for CVE-2026-13346 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Co-Authored-by: Miro Hrončok --- 10dfb6b900.patch | 347 +++++++++++++++++++++++++++++++++++++++++++++++ python-pip.spec | 3 + 2 files changed, 350 insertions(+) create mode 100644 10dfb6b900.patch diff --git a/10dfb6b900.patch b/10dfb6b900.patch new file mode 100644 index 0000000..5b56c7e --- /dev/null +++ b/10dfb6b900.patch @@ -0,0 +1,347 @@ +From 10dfb6b9005484578b386f64b9f36982e3dc6679 Mon Sep 17 00:00:00 2001 +From: Damian Shaw +Date: Tue, 30 Jun 2026 21:52:39 -0400 +Subject: [PATCH] Fix Link.filename decoding URL path twice (#14110) + +Link already percent-decodes the URL path into `self._path`, but +`Link.filename` decoded the basename again, so a doubly-encoded +separator was decoded twice: `%252F` became `%2F` in `__init__`, then +`/` in `filename`, turning the single component `a%2Fb.whl` into +`a/b.whl`. + +Drop the second decode, and add a `join_within_directory` helper so the +download-path joins treat the name as a single path component. +--- + news/14110.bugfix.rst | 1 + + src/pip/_internal/models/link.py | 63 ++++++++++--- + src/pip/_internal/network/download.py | 20 +++-- + src/pip/_internal/operations/prepare.py | 6 +- + tests/unit/test_link.py | 113 +++++++++++++++++++++++- + 5 files changed, 182 insertions(+), 21 deletions(-) + create mode 100644 news/14110.bugfix.rst + +diff --git a/news/14110.bugfix.rst b/news/14110.bugfix.rst +new file mode 100644 +index 0000000000..f7d4f78882 +--- /dev/null ++++ b/news/14110.bugfix.rst +@@ -0,0 +1 @@ ++Fix ``Link.filename`` decoding the URL path twice. +diff --git a/src/pip/_internal/models/link.py b/src/pip/_internal/models/link.py +index 0a09c66222..cbbe945c17 100644 +--- a/src/pip/_internal/models/link.py ++++ b/src/pip/_internal/models/link.py +@@ -13,6 +13,7 @@ + from typing import ( + Any, + NamedTuple, ++ NewType, + ) + + from pip._internal.exceptions import InvalidEggFragment +@@ -30,6 +31,49 @@ + logger = logging.getLogger(__name__) + + ++# A single path component: percent-decoded once and reduced to a basename, so it ++# contains no path separator and is not a ``.`` or ``..`` reference. The empty ++# string means "no component". ++PathComponent = NewType("PathComponent", str) ++ ++ ++def _to_path_component(name: str) -> PathComponent: ++ """Reduce ``name`` to a single path component, or ``""`` if it has none. ++ ++ ``os.path.basename`` drops any directory part, drive letter, or separator; ++ a ``.``, ``..``, or empty result is not a component and becomes ``""``. ++ """ ++ name = os.path.basename(name) ++ if name in ("", os.curdir, os.pardir): ++ return PathComponent("") ++ ++ return PathComponent(name) ++ ++ ++def as_path_component(name: str) -> PathComponent: ++ """Like ``_to_path_component`` but reject the empty result. ++ ++ Use where a file is about to be written, so a missing name is an error ++ rather than a silent fallback to the directory itself. ++ """ ++ component = _to_path_component(name) ++ if not component: ++ raise ValueError(f"Unexpected file name derived from URL: {name!r}") ++ ++ return component ++ ++ ++def join_within_directory(directory: str, component: PathComponent) -> str: ++ """Join a single path ``component`` onto ``directory``. ++ ++ ``component`` is a :data:`PathComponent`, so by type it has no separator and ++ is not a ``.`` or ``..`` reference; the result can never escape ``directory``. ++ Requiring ``PathComponent`` rather than ``str`` lets the type checker enforce ++ at the call site that the name was reduced to a safe component beforehand. ++ """ ++ return os.path.join(directory, component) ++ ++ + # Order matters, earlier hashes have a precedence over later hashes for what + # we will pick to use. + _SUPPORTED_HASHES = ("sha512", "sha384", "sha256", "sha224", "sha1", "md5") +@@ -424,18 +468,13 @@ def redacted_url(self) -> str: + return redact_auth_from_url(self.url) + + @property +- def filename(self) -> str: +- path = self.path.rstrip("/") +- name = posixpath.basename(path) +- if not name: +- # Make sure we don't leak auth information if the netloc +- # includes a username and password. +- netloc, user_pass = split_auth_from_netloc(self.netloc) +- return netloc +- +- name = urllib.parse.unquote(name) +- assert name, f"URL {self._url!r} produced no filename" +- return name ++ def filename(self) -> PathComponent: ++ name = _to_path_component(posixpath.basename(self.path.rstrip("/"))) ++ if name: ++ return name ++ ++ # No component in the path; fall back to the netloc, dropping any auth. ++ return _to_path_component(split_auth_from_netloc(self.netloc)[0]) + + @property + def file_path(self) -> str: +diff --git a/src/pip/_internal/network/download.py b/src/pip/_internal/network/download.py +index 039b268878..6faafb5cb0 100644 +--- a/src/pip/_internal/network/download.py ++++ b/src/pip/_internal/network/download.py +@@ -19,7 +19,12 @@ + + from pip._internal.cli.progress_bars import BarType, get_download_progress_renderer + from pip._internal.exceptions import IncompleteDownloadError, NetworkConnectionError +-from pip._internal.models.link import Link ++from pip._internal.models.link import ( ++ Link, ++ PathComponent, ++ as_path_component, ++ join_within_directory, ++) + from pip._internal.network.cache import SafeFileCache, is_from_cache + from pip._internal.network.session import CacheControlAdapter, PipSession + from pip._internal.network.utils import HEADERS, raise_for_status, response_chunks +@@ -121,11 +126,14 @@ def parse_content_disposition(content_disposition: str, default_filename: str) - + return filename or default_filename + + +-def _get_http_response_filename(resp: Response, link: Link) -> str: ++def _get_http_response_filename(resp: Response, link: Link) -> PathComponent: + """Get an ideal filename from the given HTTP response, falling back to + the link filename if not provided. ++ ++ The result is validated as a single path component, so it can be joined onto ++ a download directory without escaping it. + """ +- filename = link.filename # fallback ++ filename: str = link.filename # fallback + # Have a look at the Content-Disposition header for a better guess + content_disposition = resp.headers.get("content-disposition") + if content_disposition: +@@ -139,7 +147,7 @@ def _get_http_response_filename(resp: Response, link: Link) -> str: + ext = os.path.splitext(resp.url)[1] + if ext: + filename += ext +- return filename ++ return as_path_component(filename) + + + @dataclass +@@ -192,7 +200,9 @@ def __call__(self, link: Link, location: str) -> tuple[str, str]: + resp = self._http_get(link) + download_size = _get_http_response_size(resp) + +- filepath = os.path.join(location, _get_http_response_filename(resp, link)) ++ filepath = join_within_directory( ++ location, _get_http_response_filename(resp, link) ++ ) + with open(filepath, "wb") as content_file: + download = _FileDownload(link, content_file, download_size) + self._process_response(download, resp) +diff --git a/src/pip/_internal/operations/prepare.py b/src/pip/_internal/operations/prepare.py +index afcc0376da..3b44403e0d 100644 +--- a/src/pip/_internal/operations/prepare.py ++++ b/src/pip/_internal/operations/prepare.py +@@ -29,7 +29,7 @@ + from pip._internal.index.package_finder import PackageFinder + from pip._internal.metadata import BaseDistribution, get_metadata_distribution + from pip._internal.models.direct_url import ArchiveInfo, DirectUrl +-from pip._internal.models.link import Link ++from pip._internal.models.link import Link, join_within_directory + from pip._internal.models.wheel import Wheel + from pip._internal.network.download import Downloader + from pip._internal.network.lazy_wheel import ( +@@ -201,7 +201,7 @@ def _check_download_dir( + """Check download_dir for previously downloaded file with correct hash + If a correct file is found return its path else None + """ +- download_path = os.path.join(download_dir, link.filename) ++ download_path = join_within_directory(download_dir, link.filename) + + if not os.path.exists(download_path): + return None +@@ -687,7 +687,7 @@ def save_linked_requirement(self, req: InstallRequirement) -> None: + # No distribution was downloaded for this requirement. + return + +- download_location = os.path.join(self.download_dir, link.filename) ++ download_location = join_within_directory(self.download_dir, link.filename) + if not os.path.exists(download_location): + shutil.copy(req.local_file_path, download_location) + download_path = display_path(download_location) +diff --git a/tests/unit/test_link.py b/tests/unit/test_link.py +index c49f8547ac..bc8cb8ab9b 100644 +--- a/tests/unit/test_link.py ++++ b/tests/unit/test_link.py +@@ -1,9 +1,17 @@ + from __future__ import annotations + ++import os ++import posixpath ++ + import pytest + + from pip._internal.exceptions import InvalidEggFragment, PipError +-from pip._internal.models.link import Link, links_equivalent ++from pip._internal.models.link import ( ++ Link, ++ as_path_component, ++ join_within_directory, ++ links_equivalent, ++) + from pip._internal.utils.hashes import Hashes + + +@@ -29,6 +37,13 @@ def test_repr(self, url: str, expected: str) -> None: + ("https://example.com/path/page.html", "page.html"), + # Test a quoted character. + ("https://example.com/path/page%231.html", "page#1.html"), ++ # A doubly-encoded separator must stay encoded: the path is decoded ++ # exactly once, so the file name keeps its literal "%2F" instead of ++ # collapsing into a "/". ++ ( ++ "https://example.com/a%252Fb.whl", ++ "a%2Fb.whl", ++ ), + ( + "http://yo/myproject-1.0%2Bfoobar.0-py2.py3-none-any.whl", + "myproject-1.0+foobar.0-py2.py3-none-any.whl", +@@ -49,6 +64,52 @@ def test_filename(self, url: str, expected: str) -> None: + link = Link(url) + assert link.filename == expected + ++ @pytest.mark.parametrize( ++ "url", ++ [ ++ "https://example.com/a%252Fb.whl", ++ "https://example.com/%252e%252e%252fb.whl", ++ ], ++ ) ++ def test_filename_decoded_once_stays_single_component(self, url: str) -> None: ++ # The path is decoded exactly once, so an encoded separator stays ++ # encoded and the file name remains a single path component rather ++ # than collapsing into a "/"-separated path. ++ filename = Link(url).filename ++ assert not posixpath.isabs(filename) ++ assert posixpath.basename(filename) == filename ++ ++ @pytest.mark.parametrize( ++ "url", ++ [ ++ "https://example.com/..", ++ "https://example.com/.", ++ "https://example.com/foo/%2e%2e", ++ ], ++ ) ++ def test_filename_parent_reference_falls_back_to_netloc(self, url: str) -> None: ++ # A path that is only a "." or ".." reference has no usable file name, ++ # so filename falls back to the netloc rather than handing back a ++ # traversal component that could escape a download directory. ++ assert Link(url).filename == "example.com" ++ ++ @pytest.mark.parametrize( ++ "url", ++ [ ++ # A path-less URL whose authority looks like a traversal: the netloc ++ # fallback must still reduce to a single path component. ++ "http://..\\..\\..\\evil.whl", ++ "http://../", ++ "http://..", ++ ], ++ ) ++ def test_filename_is_always_a_path_component(self, url: str) -> None: ++ # filename must never carry a separator or parent reference, so joining ++ # it onto a directory can never escape that directory. ++ name = Link(url).filename ++ assert os.path.basename(name) == name ++ assert name not in (os.curdir, os.pardir) ++ + def test_splitext(self) -> None: + assert ("wheel", ".whl") == Link("http://yo/wheel.whl").splitext() + +@@ -244,3 +305,53 @@ def test_links_equivalent(url1: str, url2: str) -> None: + ) + def test_links_equivalent_false(url1: str, url2: str) -> None: + assert not links_equivalent(Link(url1), Link(url2)) ++ ++ ++@pytest.mark.parametrize( ++ "name", ++ [ ++ "wheel.whl", ++ "myproject-1.0+foobar.0-py2.py3-none-any.whl", ++ # A literal "%2F" is a normal file name, not a separator. ++ "a%2Fb.whl", ++ ], ++) ++def test_as_path_component_keeps_plain_name(name: str) -> None: ++ assert as_path_component(name) == name ++ ++ ++@pytest.mark.parametrize( ++ "name", ++ [ ++ os.path.join(os.sep, "abs", "pkg.whl"), ++ os.path.join("..", "pkg.whl"), ++ os.path.join("nested", "pkg.whl"), ++ ], ++) ++def test_as_path_component_reduces_to_basename(name: str) -> None: ++ # A name carrying directory components is reduced to its basename, so the ++ # result always stays inside the directory it is later joined onto. ++ assert as_path_component(name) == os.path.basename(name) ++ ++ ++@pytest.mark.parametrize("name", ["", ".", "..", "/", os.path.join("sub", "..")]) ++def test_as_path_component_rejects_empty_or_parent_reference(name: str) -> None: ++ with pytest.raises(ValueError): ++ as_path_component(name) ++ ++ ++@pytest.mark.parametrize( ++ "name", ++ [ ++ "pkg.whl", ++ # A literal "%2F" is a normal file name, not a separator. ++ "a%2Fb.whl", ++ ], ++) ++def test_join_within_directory_stays_inside(name: str) -> None: ++ # The component is joined onto the directory as its final element, so the ++ # result stays inside the directory. ++ directory = os.path.join("base", "downloads") ++ joined = join_within_directory(directory, as_path_component(name)) ++ assert joined == os.path.join(directory, name) ++ assert os.path.basename(joined) == name diff --git a/python-pip.spec b/python-pip.spec index 61fd6d1..81a54a7 100644 --- a/python-pip.spec +++ b/python-pip.spec @@ -111,6 +111,9 @@ Patch: https://github.com/pypa/pip/commit/4c6d7471de.patch # https://github.com/pypa/pip/commit/09a03f6cfa (non-existing files removed) Patch: 09a03f6cfa.patch +# CVE-2026-13346: Link.filename double URL decode allows path traversal +Patch: https://github.com/pypa/pip/commit/10dfb6b900.patch + # Remove -s from Python shebang - ensure that packages installed with pip # to user locations are seen by pip itself %undefine _py3_shebang_s