From e88f7376fe68dbf4ebaf11fad1513ce700b45860 Mon Sep 17 00:00:00 2001
From: Sarah Boyce <42296566+sarahboyce@users.noreply.github.com>
Date: Tue, 25 Feb 2025 09:40:54 +0100
Subject: [PATCH] Fixed CVE-2025-26699 -- Mitigated potential DoS in wordwrap
 template filter.

Thanks sw0rd1ight for the report.

Backport of 55d89e25f4115c5674cdd9b9bcba2bb2bb6d820b from main.

CVE: CVE-2025-26699

Upstream-Status: Backport
https://github.com/django/django/commit/e88f7376fe68dbf4ebaf11fad1513ce700b45860

Signed-off-by: Sarah Boyce <42296566+sarahboyce@users.noreply.github.com>
Signed-off-by: Saravanan <saravanan.kadambathursubramaniyam@windriver.com>

%% original patch: CVE-2025-26699.patch
---
 django/utils/text.py                          | 28 ++++++++-----------
 docs/releases/2.2.28.txt                      |  6 ++++
 .../filter_tests/test_wordwrap.py             | 12 ++++++++
 3 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/django/utils/text.py b/django/utils/text.py
index 2c4040e..c474d56 100644
--- a/django/utils/text.py
+++ b/django/utils/text.py
@@ -1,5 +1,6 @@
 import html.entities
 import re
+import textwrap
 import unicodedata
 from gzip import GzipFile
 from io import BytesIO
@@ -88,23 +89,16 @@ def wrap(text, width):
     Don't wrap long words, thus the output text may have lines longer than
     ``width``.
     """
-    def _generator():
-        for line in text.splitlines(True):  # True keeps trailing linebreaks
-            max_width = min((line.endswith('\n') and width + 1 or width), width)
-            while len(line) > max_width:
-                space = line[:max_width + 1].rfind(' ') + 1
-                if space == 0:
-                    space = line.find(' ') + 1
-                    if space == 0:
-                        yield line
-                        line = ''
-                        break
-                yield '%s\n' % line[:space - 1]
-                line = line[space:]
-                max_width = min((line.endswith('\n') and width + 1 or width), width)
-            if line:
-                yield line
-    return ''.join(_generator())
+
+    wrapper = textwrap.TextWrapper(
+        width=width,
+        break_long_words=False,
+        break_on_hyphens=False,
+    )
+    result = []
+    for line in text.splitlines(True):
+        result.extend(wrapper.wrap(line))
+    return "\n".join(result)
 
 
 class Truncator(SimpleLazyObject):
diff --git a/docs/releases/2.2.28.txt b/docs/releases/2.2.28.txt
index 7227452..7096d13 100644
--- a/docs/releases/2.2.28.txt
+++ b/docs/releases/2.2.28.txt
@@ -99,3 +99,9 @@ CVE-2024-27351: Potential regular expression denial-of-service in ``django.utils
 regular expression denial-of-service attack using a suitably crafted string
 (follow up to :cve:`2019-14232` and :cve:`2023-43665`).
 
+CVE-2025-26699: Potential denial-of-service vulnerability in ``django.utils.text.wrap()``
+=========================================================================================
+
+The ``wrap()`` and :tfilter:`wordwrap` template filter were subject to a
+potential denial-of-service attack when used with very long strings.
+
diff --git a/tests/template_tests/filter_tests/test_wordwrap.py b/tests/template_tests/filter_tests/test_wordwrap.py
index 02f8605..e6f2afb 100644
--- a/tests/template_tests/filter_tests/test_wordwrap.py
+++ b/tests/template_tests/filter_tests/test_wordwrap.py
@@ -51,3 +51,15 @@ class FunctionTests(SimpleTestCase):
             ), 14),
             'this is a long\nparagraph of\ntext that\nreally needs\nto be wrapped\nI\'m afraid',
         )
+
+    def test_wrap_long_text(self):
+        long_text = (
+            "this is a long paragraph of text that really needs"
+            " to be wrapped I'm afraid " * 20_000
+        )
+        self.assertIn(
+            "this is a\nlong\nparagraph\nof text\nthat\nreally\nneeds to\nbe wrapped\n"
+            "I'm afraid",
+            wordwrap(long_text, 10),
+        )
+
-- 
2.40.0