diff --git a/pyproject.toml b/pyproject.toml
index 4e2fd2cb5..aedba537f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,7 +28,7 @@ dependencies = [
     "flask-sqlalchemy==3.1.1",
     "flask-talisman==1.1.0",
     "flask-wtf==1.2.2",
-    "flask==3.0.3",
+    "flask==3.1.0",
     "govuk-frontend-jinja==2.8.0",
     "greenlet==3.1.1",
     "gunicorn[gevent]==23.0.0",
diff --git a/uv.lock b/uv.lock
index 1fe8e6409..c6335e5b9 100644
--- a/uv.lock
+++ b/uv.lock
@@ -526,7 +526,7 @@ wheels = [
 
 [[package]]
 name = "flask"
-version = "3.0.3"
+version = "3.1.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "blinker" },
@@ -535,9 +535,9 @@ dependencies = [
     { name = "jinja2" },
     { name = "werkzeug" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/41/e1/d104c83026f8d35dfd2c261df7d64738341067526406b40190bc063e829a/flask-3.0.3.tar.gz", hash = "sha256:ceb27b0af3823ea2737928a4d99d125a06175b8512c445cbd9a9ce200ef76842", size = 676315 }
+sdist = { url = "https://files.pythonhosted.org/packages/89/50/dff6380f1c7f84135484e176e0cac8690af72fa90e932ad2a0a60e28c69b/flask-3.1.0.tar.gz", hash = "sha256:5f873c5184c897c8d9d1b05df1e3d01b14910ce69607a117bd3277098a5836ac", size = 680824 }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/61/80/ffe1da13ad9300f87c93af113edd0638c75138c42a0994becfacac078c06/flask-3.0.3-py3-none-any.whl", hash = "sha256:34e815dfaa43340d1d15a5c3a02b8476004037eb4840b34910c6e21679d288f3", size = 101735 },
+    { url = "https://files.pythonhosted.org/packages/af/47/93213ee66ef8fae3b93b3e29206f6b251e65c97bd91d8e1c5596ef15af0a/flask-3.1.0-py3-none-any.whl", hash = "sha256:d667207822eb83f1c4b50949b1623c8fc8d51f2341d65f72e1a1815397551136", size = 102979 },
 ]
 
 [[package]]
@@ -886,7 +886,7 @@ requires-dist = [
     { name = "cssmin", specifier = "==0.2.0" },
     { name = "dataclass-dict-convert", specifier = "==1.7.4" },
     { name = "email-validator", specifier = "==2.2.0" },
-    { name = "flask", specifier = "==3.0.3" },
+    { name = "flask", specifier = "==3.1.0" },
     { name = "flask-assets", specifier = "==2.1.0" },
     { name = "flask-babel", specifier = "==4.0.0" },
     { name = "flask-compress", specifier = "==1.17" },