[5.1.x] Fixed CVE-2024-56374 -- Mitigated potential DoS in IPv6 validation.

Thanks Saravana Kumar for the report, and Sarah Boyce and Mariusz
Felisiak for the reviews.

Co-authored-by: Natalia <124304+nessita@users.noreply.github.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/docs/releases/4.2.18.txt b/docs/releases/4.2.18.txt
index ae0c4e3334..fef91d9150 100644
--- a/docs/releases/4.2.18.txt
+++ b/docs/releases/4.2.18.txt
@@ -5,3 +5,15 @@ Django 4.2.18 release notes
 *January 14, 2025*
 
 Django 4.2.18 fixes a security issue with severity "moderate" in 4.2.17.
+
+CVE-2024-56374: Potential denial-of-service vulnerability in IPv6 validation
+============================================================================
+
+Lack of upper bound limit enforcement in strings passed when performing IPv6
+validation could lead to a potential denial-of-service attack. The undocumented
+and private functions ``clean_ipv6_address`` and ``is_valid_ipv6_address`` were
+vulnerable, as was the  :class:`django.forms.GenericIPAddressField` form field,
+which has now been updated to define a ``max_length`` of 39 characters.
+
+The :class:`django.db.models.GenericIPAddressField` model field was not
+affected.