diff --git a/homeassistant/package_constraints.txt b/homeassistant/package_constraints.txt
index 319307efe58..f80c607c4ce 100644
--- a/homeassistant/package_constraints.txt
+++ b/homeassistant/package_constraints.txt
@@ -20,7 +20,7 @@ bluetooth-auto-recovery==1.3.0
 bluetooth-data-tools==1.19.0
 cached_ipaddress==0.3.0
 certifi>=2021.5.30
-ciso8601==2.3.0
+ciso8601==2.3.1
 cryptography==42.0.5
 dbus-fast==2.21.1
 fnv-hash-fast==0.5.0
diff --git a/pyproject.toml b/pyproject.toml
index 1fe2da07240..fec3d83d5e7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,7 +34,7 @@ dependencies    = [
     "awesomeversion==24.2.0",
     "bcrypt==4.0.1",
     "certifi>=2021.5.30",
-    "ciso8601==2.3.0",
+    "ciso8601==2.3.1",
     # When bumping httpx, please check the version pins of
     # httpcore, anyio, and h11 in gen_requirements_all
     "httpx==0.26.0",
diff --git a/requirements.txt b/requirements.txt
index 7f1ae3c4f32..99ae9fb1811 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -14,7 +14,7 @@ atomicwrites-homeassistant==1.4.1
 awesomeversion==24.2.0
 bcrypt==4.0.1
 certifi>=2021.5.30
-ciso8601==2.3.0
+ciso8601==2.3.1
 httpx==0.26.0
 home-assistant-bluetooth==1.12.0
 ifaddr==0.2.0