[6.0.x] Fixed CVE-2025-64458 -- Mitigated potential DoS in HttpResponseRedirect/HttpResponsePermanentRedirect on Windows.

Thanks Seokchan Yoon for the report, Markus Holtermann for the
triage, and Jake Howard for the review.

Follow-up to CVE-2025-27556 and 39e2297210d9d2938c75fc911d45f0e863dc4821.

Backport of c880530ddd4fabd5939bab0e148bebe36699432a from main.

1 files changed, 7 insertions, 2 deletions

diff --git a/django/http/response.py b/django/http/response.py
index 40b2d7089d..020b2fcf3a 100644
--- a/django/http/response.py
+++ b/django/http/response.py
@@ -22,7 +22,7 @@ from django.utils import timezone
 from django.utils.datastructures import CaseInsensitiveMapping
 from django.utils.encoding import iri_to_uri
 from django.utils.functional import cached_property
-from django.utils.http import content_disposition_header, http_date
+from django.utils.http import MAX_URL_LENGTH, content_disposition_header, http_date
 from django.utils.regex_helper import _lazy_re_compile
 
 _charset_from_content_type_re = _lazy_re_compile(
@@ -631,7 +631,12 @@ class HttpResponseRedirectBase(HttpResponse):
     def __init__(self, redirect_to, preserve_request=False, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self["Location"] = iri_to_uri(redirect_to)
-        parsed = urlsplit(str(redirect_to))
+        redirect_to_str = str(redirect_to)
+        if len(redirect_to_str) > MAX_URL_LENGTH:
+            raise DisallowedRedirect(
+                f"Unsafe redirect exceeding {MAX_URL_LENGTH} characters"
+            )
+        parsed = urlsplit(redirect_to_str)
         if preserve_request:
             self.status_code = self.status_code_preserve_request
         if parsed.scheme and parsed.scheme not in self.allowed_schemes: