Security fix for CVE-2026-4519

Resolves: RHEL-158117

00478-cve-2026-4519.patch

@@ -0,0 +1,123 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: tomcruiseqi <tom33qi@gmail.com>
+Date: Wed, 25 Mar 2026 02:23:45 +0800
+Subject: 00478: CVE-2026-4519
+
+Reject leading dashes in webbrowser URLs (GH-143931) (GH-146359)
+
+Cherry-picked from Python 3.10: ad4d5ba32af4d80b0dfa2ba9d8203bfb219e60a5
+
+(cherry picked from commit 82a24a4442312bdcfc4c799885e8b3e00990f02b)
+
+Co-authored-by: Seth Michael Larson <seth@python.org>
+---
+ Lib/test/test_webbrowser.py                        |  5 +++++
+ Lib/webbrowser.py                                  | 14 ++++++++++++++
+ .../2026-01-16-12-04-49.gh-issue-143930.zYC5x3.rst |  1 +
+ 3 files changed, 20 insertions(+)
+ create mode 100644 Misc/NEWS.d/next/Security/2026-01-16-12-04-49.gh-issue-143930.zYC5x3.rst
+
+diff --git a/Lib/test/test_webbrowser.py b/Lib/test/test_webbrowser.py
+index 519a9432ab..f8e9234db8 100644
+--- a/Lib/test/test_webbrowser.py
++++ b/Lib/test/test_webbrowser.py
+@@ -55,6 +55,11 @@ class GenericBrowserCommandTest(CommandTestMixin, unittest.TestCase):
+                    options=[],
+                    arguments=[URL])
+ 
++    def test_reject_dash_prefixes(self):
++        browser = self.browser_class(name=CMD_NAME)
++        with self.assertRaises(ValueError):
++            browser.open(f"--key=val {URL}")
++
+ 
+ class BackgroundBrowserCommandTest(CommandTestMixin, unittest.TestCase):
+ 
+diff --git a/Lib/webbrowser.py b/Lib/webbrowser.py
+index 6023c1e138..f5349dbce5 100755
+--- a/Lib/webbrowser.py
++++ b/Lib/webbrowser.py
+@@ -154,6 +154,12 @@ class BaseBrowser(object):
+     def open_new_tab(self, url):
+         return self.open(url, 2)
+ 
++    @staticmethod
++    def _check_url(url):
++        """Ensures that the URL is safe to pass to subprocesses as a parameter"""
++        if url and url.lstrip().startswith("-"):
++            raise ValueError(f"Invalid URL: {url}")
++
+ 
+ class GenericBrowser(BaseBrowser):
+     """Class for all browsers started with a command
+@@ -171,6 +177,7 @@ class GenericBrowser(BaseBrowser):
+ 
+     def open(self, url, new=0, autoraise=True):
+         sys.audit("webbrowser.open", url)
++        self._check_url(url)
+         cmdline = [self.name] + [arg.replace("%s", url)
+                                  for arg in self.args]
+         try:
+@@ -191,6 +198,7 @@ class BackgroundBrowser(GenericBrowser):
+         cmdline = [self.name] + [arg.replace("%s", url)
+                                  for arg in self.args]
+         sys.audit("webbrowser.open", url)
++        self._check_url(url)
+         try:
+             if sys.platform[:3] == 'win':
+                 p = subprocess.Popen(cmdline)
+@@ -256,6 +264,7 @@ class UnixBrowser(BaseBrowser):
+ 
+     def open(self, url, new=0, autoraise=True):
+         sys.audit("webbrowser.open", url)
++        self._check_url(url)
+         if new == 0:
+             action = self.remote_action
+         elif new == 1:
+@@ -357,6 +366,7 @@ class Konqueror(BaseBrowser):
+ 
+     def open(self, url, new=0, autoraise=True):
+         sys.audit("webbrowser.open", url)
++        self._check_url(url)
+         # XXX Currently I know no way to prevent KFM from opening a new win.
+         if new == 2:
+             action = "newTab"
+@@ -441,6 +451,7 @@ class Grail(BaseBrowser):
+ 
+     def open(self, url, new=0, autoraise=True):
+         sys.audit("webbrowser.open", url)
++        self._check_url(url)
+         if new:
+             ok = self._remote("LOADNEW " + url)
+         else:
+@@ -599,6 +610,7 @@ if sys.platform[:3] == "win":
+     class WindowsDefault(BaseBrowser):
+         def open(self, url, new=0, autoraise=True):
+             sys.audit("webbrowser.open", url)
++            self._check_url(url)
+             try:
+                 os.startfile(url)
+             except OSError:
+@@ -629,6 +641,7 @@ if sys.platform == 'darwin':
+ 
+         def open(self, url, new=0, autoraise=True):
+             sys.audit("webbrowser.open", url)
++            self._check_url(url)
+             assert "'" not in url
+             # hack for local urls
+             if not ':' in url:
+@@ -666,6 +679,7 @@ if sys.platform == 'darwin':
+             self._name = name
+ 
+         def open(self, url, new=0, autoraise=True):
++            self._check_url(url)
+             if self._name == 'default':
+                 script = 'open location "%s"' % url.replace('"', '%22') # opens in default browser
+             else:
+diff --git a/Misc/NEWS.d/next/Security/2026-01-16-12-04-49.gh-issue-143930.zYC5x3.rst b/Misc/NEWS.d/next/Security/2026-01-16-12-04-49.gh-issue-143930.zYC5x3.rst
+new file mode 100644
+index 0000000000..0f27eae99a
+--- /dev/null
++++ b/Misc/NEWS.d/next/Security/2026-01-16-12-04-49.gh-issue-143930.zYC5x3.rst
+@@ -0,0 +1 @@
++Reject leading dashes in URLs passed to :func:`webbrowser.open`

python3.9.spec

@@ -17,7 +17,7 @@ URL: https://www.python.org/
 #global prerel ...
 %global upstream_version %{general_version}%{?prerel}
 Version: %{general_version}%{?prerel:~%{prerel}}
-Release: 5%{?dist}
+Release: 6%{?dist}
 License: Python
 
 
@@ -476,6 +476,14 @@ Patch475: 00475-cve-2025-15367.patch
 # gh-144125: email: verify headers are sound in BytesGenerator
 Patch476: 00476-cve-2026-1299.patch
 
+# 00478 # 88bb1e37c971fd1d6bda82a68b5ad873ed099f08
+# CVE-2026-4519
+#
+# Reject leading dashes in webbrowser URLs (GH-143931) (GH-146359)
+#
+# Cherry-picked from Python 3.10: ad4d5ba32af4d80b0dfa2ba9d8203bfb219e60a5
+Patch478: 00478-cve-2026-4519.patch
+
 # (New patches go here ^^^)
 #
 # When adding new patches to "python" and "python3" in Fedora, EL, etc.,
@@ -1887,6 +1895,10 @@ CheckPython optimized
 # ======================================================
 
 %changelog
+* Thu Mar 26 2026 Lumír Balhar <lbalhar@redhat.com> - 3.9.25-6
+- Security fix for CVE-2026-4519
+Resolves: RHEL-158117
+
 * Mon Mar 09 2026 Tomáš Hrnčiar <thrnciar@redhat.com> - 3.9.25-5
 - Rebuilding previous fixes for different build target
 Related: RHEL-143117, RHEL-143174, RHEL-144897