From bd562dd5c7178ef4f0d4fb862a74d9f1fef4aed4 Mon Sep 17 00:00:00 2001
From: Martin Hauser <mhauser@netboxlabs.com>
Date: Tue, 14 Jul 2026 18:25:56 +0200
Subject: [PATCH] Fixes #22662: Fix database overflow when saving Cables with
 large lengths (#22668)

---
 .../0238_alter_cable__abs_length.py           | 16 +++++++++++
 netbox/dcim/models/cables.py                  |  2 +-
 netbox/dcim/tests/test_models.py              | 28 +++++++++++++++++++
 3 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 netbox/dcim/migrations/0238_alter_cable__abs_length.py

diff --git a/netbox/dcim/migrations/0238_alter_cable__abs_length.py b/netbox/dcim/migrations/0238_alter_cable__abs_length.py
new file mode 100644
index 000000000..f963e400c
--- /dev/null
+++ b/netbox/dcim/migrations/0238_alter_cable__abs_length.py
@@ -0,0 +1,16 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dcim', '0237_module_remove_local_context_data'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='cable',
+            name='_abs_length',
+            field=models.DecimalField(blank=True, decimal_places=4, max_digits=14, null=True),
+        ),
+    ]
diff --git a/netbox/dcim/models/cables.py b/netbox/dcim/models/cables.py
index a7d1e366b..d30801ed3 100644
--- a/netbox/dcim/models/cables.py
+++ b/netbox/dcim/models/cables.py
@@ -133,7 +133,7 @@ class Cable(PrimaryModel):
     )
     # Stores the normalized length (in meters) for database ordering
     _abs_length = models.DecimalField(
-        max_digits=10,
+        max_digits=14,
         decimal_places=4,
         blank=True,
         null=True
diff --git a/netbox/dcim/tests/test_models.py b/netbox/dcim/tests/test_models.py
index 6f8139835..c09adc337 100644
--- a/netbox/dcim/tests/test_models.py
+++ b/netbox/dcim/tests/test_models.py
@@ -1,3 +1,5 @@
+from decimal import Decimal
+
 from django.core.exceptions import ValidationError
 from django.db.models.signals import post_save
 from django.test import TestCase, tag
@@ -2227,6 +2229,32 @@ class CableTestCase(TestCase):
         interface = Interface(device=device, name='tmp', cable=cable)
         self.assertIsNone(interface.path)
 
+    def test_cable_length_normalization_large_kilometer_value(self):
+        """
+        A large kilometer length must pass validation and fit in the normalized length field.
+        """
+        cable = Cable.objects.first()
+        cable.length = Decimal('1234')
+        cable.length_unit = CableLengthUnitChoices.UNIT_KILOMETER
+        cable.full_clean()
+        cable.save()
+        cable.refresh_from_db()
+
+        self.assertEqual(cable._abs_length, Decimal('1234000.0000'))
+
+    def test_cable_length_normalization_maximum_mile_value(self):
+        """
+        The maximum length value expressed in miles must fit in the normalized length field.
+        """
+        cable = Cable.objects.first()
+        cable.length = Decimal('999999.99')
+        cable.length_unit = CableLengthUnitChoices.UNIT_MILE
+        cable.full_clean()
+        cable.save()
+        cable.refresh_from_db()
+
+        self.assertEqual(cable._abs_length, Decimal('1609343983.9066'))
+
 
 class CableTerminationTestCase(TestCase):